THE @EAMMAYEGN CF
inPENTY‘Mi-‘MRES ANY} TeHEXYMMINE

Thesis §or {‘Em Deqru of DH. D.
ME€§¥EGAN HATE UNIVERSETY

Mama Anand
3.967

t-.. 'I '.
LIBRAR 1' ““1 *
Michigan State
University

*d

  
 

THESIS

   

This is to certify that the

thesis entitled

The Deamination of
l-Pentylamines And l-Hexylamine

presented by

MonaAnand

has been accepted towards fulfillment
of the requirements for

_Eh.._D.._ degree in _Chemistm

1% f [GAME

Major professor

Date December 153 i96L

0-169

ABSTRACT

THE DEAMINATION OF l-PENTYLAMINES AND l-HEXYLAMINE

by Mona Anand

The equilibrating protonated cyclOpropanes have been
postulated as the intermediates responsible for the forma-
tion of cycloprOpane as well as the scrambling of carbon
skeleton in the deamination of l-propylamine. In contrast,
neopentyl amine on deamination does not yield any cyclopro—
pane product, but only products of a simple 1,2-methyl
shift. Deamination of other aliphatic amines has not been
studied in great detail to know the rearrangements these
systems might undergo. Furthermore, 1,2—hydride shifts are
known to occur in many carbonium ion reactions, as are also
1,3-hydride shifts in certain systems. Hydride shifts of
higher order like 1,5—, 1,6- are not of common occurrence
in the non-cyclic aliphatic systems. Such hydride shifts
are restricted to medium rings as exemplified by trans—
annular hydride shifts, as well as to the rigid polycyclic
systems, in which the geometry of the molecules permits the
formation of a six-membered cyclic transition state. The
purpose of this study was to obtain information about the
significance of intermediacy of protonated cyclopropane and
of the occurrence of 1,5— and 1,6-hydride shifts in deamina-
tion of l-pentyl and 1-hexyl amines. To this end, l—pentyl-
amines dideuterated in positions one, two, and three and

1—hexylamine-1,1—d2 were deaminated and the alcohol products

Mona Anand
used as the basis for the conclusions reached at from this
investigation.

From the deamination of 1—pentyl and 1—hexyl amines,
1-pentanol, 2-pentanol, 3-pentanol, and the corresponding
hexanols were the only alcohol products. The mass spectral
data showed, in each case, that the normal alcohols were iso—
tope-position unrearranged. This observation ruled out any
possible 1,5- or 1,6-hydride shifts as well as any alkyl
shifts. Also any alkyl bridged symmetrical ions (I) and the
equilibrating protonated cyclopropanes (II) and (II')

are unimportant

 

R R R
l I I
CH CH~~. .u»CH
/ 2 e‘, ,,
// +\\ \ +/ H\ +/’ \
/ _____> \b/ If
CH2 CH2 CH2 H2 H2— CH2
I II II'
R = prOpyl - l-hexyl
R = Ethyl — l—pentyl

The secondary alcohols are the result of successive
reversible 1,2-hydride shifts. No definite conclusions
regarding rearrangement by combination of 1,3-hydride and
1,2-hydride shifts could be drawn from the available data.
However, it seemed reasonable on the basis of their non-
occurrence in l-butyl system, to assume that 1,3—hydride
shifts do not occur in the present systems.

It was also established that in the deamination of

l-pentylamines, the alcohols are formed irreversibly from
the unrearranged or rearranged carbonium ions or their

precursors derived from the starting amines.

THE DEAMINATION OF 1-PENTYLAMINES AND 1-HEXYLAMINE

BY

Mona Anand

A THESIS

Submitted to
Michigan State University
in partial fulfillment of the requirements
for the degree of

DOCTOR OF PHILOSOPHY

Department of Chemistry

1967

’3 44?”; 0t
SAC'(~$

To Mother

ii

ACKNOWLEDGMENTS

The author is very grateful to Dr. G. J. Karabatsos
for his continued assistance and guidance throughout the
course of the work which made this thesis possible. She
also wishes to thank him for the tolerance and the considera-
tion shown throughout the course of this investigation.

The invaluable assistance in the mass spectral analysis,
rendered by Mr. Seymour Meyerson of the American Oil
Company, Whiting, Indiana is greatly appreciated.

The financial support from the Petroleum Research Fund

is gratefully acknowledged.

iii

TABLE OF CONTENTS

Page
ACKNOWLEDGMENTS . . . . . . . . . . . . . . . . . . iii
LIST OF TABLES . . . . . . . . . . . . . . . . . . vi
INTRODUCTION . . . . . . . . . . . . . . . . . . . 1
RESULTS . . . . . . . . . . . . . . . . . . . . . . 17
1. 1-Pentylamine—1,1-d2 . . . . . . . . . . . 17
2. 1-Pentylamine-2,2—_d_2 . . . . . . . . . . . 29
3. 1-Pentylamine-3,3fid2 . . . . . . . . . . . 34
4. 1—Hexylamine—1,1-g2 . . . . . . . . . . . 41
DISCUSSION . . . . . . . . . . . . . . . . . . . . 55
1. Normal Alcohols . . . . . . . . . . . . . 55
2. Secondary Alcohols . . . . . . . . . . . . 57
SUMMARY . . . . . . . . . . . . . . . . . . . . . . 62
EXPERIMENTAL . . . . . . . . . . . . . . . . . . . 63
1. Preparation of Trimethylsilyl Ether

Derivatives of Pentyl and Hexyl Alcohols . 63

2. Preparation of 1-Pentylammonium Perchlorate-
1,1—g2 . . . . . . . . . . . . . . . . . . 63

3. Deamination of 1-Pentylammonium Perchlorate-
1,1-g2 . . . . . . . . . . . . . . . . . . 64

4. Preparation of 1-Pentylammonium Perchlorate-
2,2-d2 . . . . . . . . . . . . . . . . . . 65

5. Preparation of 1-Pentylammonium Perchlorate-
3,3-d2 . . . . . . . . . . . . . . . . . . 69

6. Deamination of 1~Pentylammonium Perchlorate-
2,2-g2 and 1-Pentylammonium Perchlorate-
3,3-g2 . . . . . . . . . . . . . . . . . . 71

iv

TABLE OF CONTENTS (Cont.)
Page
7. Preparation of Authentic Deuterated Alcohols 72

8. Preparation of 1-Hexylammonium Perchlorate-
1,1-g2 . . . . . . . . . . . . . . . . . . . 74

9. Deamination of 1-Hexylammonium Perchlorate-

1,1-g2 . . . . . . . . . . . . . . . . . . . 75
10. Preparation of Authentic 1-Hexanol-1,1-§2 . 75
BIBLIOGRAPHY . . . . . . . . . . . . . . . . . . . . 77

TABLE

II.

III.

IV.

VI.

VII.

VIII.

XI.

XII.

XIII.

LIST OF TABLES

Page
Mass Spectrum of unlabeled
CH3CH2CH2CH2CHZOSi(CH3)3 . . . . . . . . . 19
Mass spectrum of authentic
CH3CH2CH2CH2CH2CDZOSi(CH3)3 . . . . . . . . 20

Mass spectrum of CH3CH2CH2CH2CHZOSi(CH3)3
from 1-pentanol obtained from the deamina-
tion of 1-pentylammonium perchlorate-1,1—dz 21

Mass spectrum of unlabeled
CH3CH2CH2CH(CH3)OSi(CH3)3 . . . . . . . . . 22

Mass spectrum of authentic
CH3CH2CH2CD(CH3)OSi(CH3)3 . . . . . . . . . 23

Mass spectrum of unlabeled
(CH3CH2)2CHOSi(CH3)3 . . . . . . . . . . . 24

Mass spectrum of authentic
(CH3CH2)2CDOSi(CH3)3 . . . . . . . . . . . 25

Mass Spectrum of CH3CH CHZCH(CH3)OSi(CH3)3

and (CH3CH2)2CHOSi(CH333 from the mixture

of 2-pentanol and 3-pentanol obtained from

the deamination of 1-pentylammonium perchlor-
ate-1,1-§2 . . . . . . . . . . . . . . . . 26

Mass spectrum of authentic . , V
CH3CH2CH2CD2CHZOSi(CH3)3 . . . . . . . . . 31

Mass spectrum of CH3CH2CH2CH2CHZOSi(CH3)3
from 1—pentanol obtained from the deamina-
tion of l-pentylammonium perchlorate-2,2-g2 32

Mass spectrum of CH3CH CHZCH(CH3)OSi(CH3)3

and (CH3CH2)2CHOSi(CH333 from the mixture

of 2-pentanol and 3-pentanol obtained from

the deamination of 1-pentylammonium per-
chlorate-2,2-d2 . . . . . . . . . . . . . . 33

Mass Spectrum of authentic
CH3CH2CD2CH2CHZOSi(CH3)3 . . . . . . . . . 35

Mass spectrum of CH3CH2CH2CH2CHZOSi(CH3)3
from 1-pentanol obtained from the deamina-
tion of l-pentylammonium perchlorate-3,3-d2 36

Vi

LIST OF TABLES (Cont.)

TABLE

XIV.

XV.

XVI.

XVII.

XVIII.

XIX.

XXIII.

XXIV.

Mass spectrum of CH3CH CHZCH(CH3)OSi(CH3)3
and (CH3CH2)2CHOSi(CH333 from the mixture of
2—pentanol and 3—pentanol obtained from the

deamination of 1-pentylammonium perchlorate-
3,3-g2 . . . . . . . . . . . . . . . . .

Results of the mass spectral analysis of
authentic labeled alcohols . . . . .

Results of the mass spectral analysis of
trimethylsilyl ethers of the alcohols
obtained from the deamination of labeled
1-pentylamines . . . . . . . . . . . .

Mass spectrum of unlabeled
CH3CH2CH2CH2CH2CHZOSi(CH3)3 . . . . .

Mass spectrum of authentic
CH3CH2CH2CH2CH2CDZOSi(CH3)3 . . . . . . . .

Mass spectrum of CH3CH2CH2CH2CH2CH2051(CH3)3
from 1-hexanol obtained from the deamination
of 1-hexylammonium perchlorate-1,1112 . . .

Mass Spectrum of CH3CH2CH2CH2CH(CH3)OSi(CH3)3
Mass spectrum of CH3CH2CH2CH(CH2CH3)OSi(CH3)3

Mass spectrum of the trimethylsilyl ethers
of the mixture of 2-hexanol and 3-hexanol
obtained from the deamination of 1-hexyl
ammonium perchlorate-1,1-d2 . . . . .

Percentage compositions of the 2-pentanol,
2-hexanol and 3 -hexanol products obtained
from the deamination of labeled 1-pentyl-
and 1-hexylamines . . . . . . . . . . . . .

Percentage compositions of the secondary

alcohols obtained from the deamination of
labeled 1-pentyl and 1—hexylamines . . . . .

Vii

Page

37

38

39

42

43

44

45

46

47

53

54

IN TRODUCT I ON

Ever since it was recognized that carbonium ions exist
as intermediates (short-as well as long-lived) in many
organic reactions (1, 2, 3), much work has been carried out
to determine the nature of these intermediates and the man-
ner in which they rearrange.

In contrast to intramolecular 1,2-hydride shifts, which
have been known to occur in many pinacol rearrangements and
solvolytic reactions,few examples of hydride shifts of
higher order are known. 1,3-Hydride shifts have been known
to occur in certain reactions (4, 5). In 1953, Roberts and
Halmann (6) prOposed that deamination of 1-aminopropane-1-14c
proceeded partly by the methyl bridged ion (I) to give iso-
topically rearranged products. They rejected the possibility
that the rearrangement might occur by the intervention of

the 1,3-hydrogen bridged ion (II), on the basis that an

 

/C\H3 /’H\\
// 'l’ \\ // + 11‘
, 14 . CH2 CH2
CH2"‘ CH2 /
CH2
I II

hydrogen bridged ion was found to be unimportant in the de-
amination of ethylamine (7). Later, Reutov and Shatkina
(8,9,10) reinvestigated the deamination of l-aminOpropane

and explained their results by suggesting that the rearrange—
ment proceeded either by 1,3-hydride shifts with the hydrogen

1

2
bridged ion (III) as a transition state, or by successive

1,2-hydride shifts.

III

In 1962, Karabatsos and Orzech (11) reported that the
1-propyl cation produced in the deamination of 1-propyl—
mmine-l,1,2,2-§A rearranges mainly, if not exclusively, by
way of 1,3—hydride shifts to give isotope-position re—
arranged products. Their observation was based on the study
of the nmr spectra of 1-propanol obtained as one of the
products in the reaction. The results showed that the re—
arrangement could be better explained by sequence (1)

rather than (2)

+

+ 1, rv
CH3CD2CD2 '_—'3—_I'—I_> CH2CD2CD2H £29_> HOCH2CD2CD2H (1)
+ 1,2 D:~ + 1,2 H:~ + H20
CH3CD2CD2 -———--> CH3CDCD3 -—-————-> CHZCDHCDa >CH2CDHCD3 (2)
I

OH
Lee and Kruger (12,13) investigated further the deamina-

tion of isotopically labelled l-aminopropanes. In the de-
amination of 1-aminopropane 1-3, 1.2% of tritium ended up

at C-2 and 1.6-1.7% at C-3 of the 1-propanol product. In
the case of l-aminopropane 1-14C, 2.2% of 14C was found at
C-2 and 1.9% at C-3. These results indicated that about
4—6% of 1-propanol obtained in the deamination was derived

from protonated cyclopropane. The data, however, did not

3
distinguish between face-protonated (IV) and edge-protonated

cyclopropanes (Va, Vb, Vc).

C32 2 \ 2 CH2
+H \\ +}I __°. H/+// > \\\
\ I <— I / <—'_ CHz-"’""CH2
\ I l/ \ x/
\
CH2-—-—-CH2 CH2—————c 2 cH2—————CH2 ‘sr
IV Va Vb Vc

At the same time, Karabatsos, Orzech and Meyerson (14)
carried out the deamination of deuterated 1-aminopropanes
and determined the isotopic composition of the a-methylene
group of the 1—propanol product of the reaction by studying
the mass spectra of the trimethylsilyl derivative of the
alcohol. The results of their study showed that the a-

methylene group of 1-propanol had the following composition:

400

 

CH3CH2CD2NH2 > C2H5CD20H + C2H4D-CHDOH + C2H3D2-CH20H

100% g2 I 95.7% II 1.0% III 3.3%

400

 

CH3CD2CH2NH2 > C2H5CD20H "l" C2H4D’CHDOH + C2H3CD2-CH20H

100% g2 I' 1.2% II' 0.9% III' 97.9%

They concluded from the above results that about 5% of
1-propanol arises from equilibration of edge-protonated
cyclopropanes and 95% from an intermediate or intermediates
leading to isotOpically unrearranged products. Both
mechanisms A and B were found to be consistent with the

results.

 

CH3CH2CD2Z

VI:¥/§/// or + A
Ti CH3CH2CD2 t1

 

l
CH2 : +;D CH2 ------ ‘CD2 CH2 CD2
\' ,

./

cfiD A VI. VII

f1 VIII CH3CD2CHZZ

or

CH + CH
/:\ 3‘ CH3CD2CH2 /:\\\‘
CHD : +;D CD2 : +;>H
\:’// :///

CH2 H2

VIII'

ll VII'

egg
/: \
CHD : +§H < > etc.

. /
\é//

HD

IX

More recently Karabatsos, Fry, and Meyerson (15) studied
the aluminum bromide catalyzed isomerization of lebromo-
propane to 2-brom0propane at various stages of completion.
The products were converted to alcohols by silver ion as-
sisted solvolysis. On the basis of the nmr and the mass
spectral analyses of products and their derivatives, they
found that while the 2-propy1 product was the result of a
single intramolecular 1,2—hydride shift, 1-bromopropane was
extensively isotope-position rearranged. They interpreted
this result in terms of equilibrating edge-protonated cyclo-

propanes.

5

Protonated cyclOpropanes have been suggested as inter—
mediates in a variety of reactions, such as treatment of
CyclOpropane with deuteriosulfuric acid (16,17), bromination
(18) and acylation (19) of cyclopropane, and hydrogen
bromide catalyzed gas phase rearrangement of cyclopropane
to pmopene (20). Various rearrangements occurring in the

Imuss spectrometer (21,22) have also been interpreted in

terTns of protonated cyclopropanes.

It has been reported in the literature that the neo-
,per1t;yl system” on deoxidation (23,24), on deamination (25),
on. snolvolysis (26), or on acid treatment of neopentyl

alochol (27), gives rise to E-pentyl products by a simple

1:2—methyl shift. It is conceivable that these rearrange-

ments in the neopentyl cation might occur via the methyl

IDITiciggegd cyclopropane (X) or the protonated cyclopropane (XI)

 

 

[Cl-{3 C52-“‘
, .\ \ +7H
’ + \ < > \\ ’/
(CH3)2d;::::::CH2 (CH3)2C‘——‘—_36H2
X XI

In the study of the deamination of neopentyl-

anl‘ . .
lne in aqueous nitrous ac1d, Karabatsos, Orzech, and
Me:
§’Galr.‘son (27) have rigorously excluded the intervention of

pr
C)t:s:nqated cyclopropane (XI) as an intermediate, leading

tc>
JEi“pentyl product.

If the methyl bridged cyclOpropane (X)
WQre

an intermediate leading to 37amyl cation, its inter-

vex-1 ,
t:9143n would have been detected by the formation of some

 

no"

.
an“

a.

H‘-

.4
I
‘II

6
amount of 1,1—dimethyl cyclOpropane. Since, the latter was
not found as a product they stated that apparently (X) re-
arranges to a very stable cation (XII) faster than it equi-
librates with (X1) or forms 1,1—dimethyl cycloprOpane by

loss of a proton.

+ / \ + .
(CH3)3CCH2 > CEQ\~,/’ + ‘\ > (CH3)2C'CH2CH3

 

 

X XII

CH2_

/__C\C:

XI

CH3

ZKarabatsos, 35 a; (28) have called attention to the
féi<=12 . that in the deamination of isobutylamine-1,1—g2, the
meitlllzy'l bridged substituted cycloprOpane rearranges QUiCle
tc’ 'tllle more stable 2-butyl cation but not before it loses
a 35>3C‘c>ton to give a small amount of methyl cyclopropane.
It: ' Iaowever, does not equilibrate with protonated cyclo-
pr QE>anes. Their observations were based on the study of

t
}lea rnnr and the mass spectra of the trimethylsilyl deriva-

t‘
J;\r€3 of the secondary butyl alcohol product. The follow-

irls: - .
Inechanism was proposed to explain the results.

 

 

/ \ \ \\‘
+ / \ \ +?
(CH3)2CHCD2 > ’ _:’___\\ > \ /
CH3CH — CD2 CH3CI‘I_—‘— CD2
11,2 CH3~
+ 1,2 D ~ + H 0

CH3CHDCDCH3 <—-—-———- CH3CHCD2CH3 —2——> CHa-CHCDZCHa

(H20 OH
CH3CHDCDCH3

OH

Isobutylamine illustrates the effect of an alkyl
group at C—2 of the propyl system. To study the effect of
the alkyl group at C-3 of the propyl system Karabatsos and

coworkers deaminated deuterated n-butylamines in aqueous
nitrous acid (29). The isotopic compositions of the rear—

ranged secondary butyl alcohol products were

CH3 (CI-12)2CD2NH2 —> CH3CH2CHCHD2 -+ CH3CHCH2CHDZ
OH OH
100% g2 74% 26%

c
H3CH2cDZCH2NH2 —> CH3CH2CDCH2D + CHaCHCHDCHzD + CH3C'3HCD2CH3
OH \ OH OH /

1 00% 75% 25%

CH
3QD2CH2CH2NH2 —> CH3CD2CHCH3 + CH3CDCHDCH3

OH OH
100% 512 83% 17%
If
1 . 3—hydride shifts were taking place in the butyl sys-
te
m ’ the deamination of 1—butylamine-3,3-d2 would undergo

1‘83
J:‘3Z‘angement according to the following scheme

8

 

 

+ 1 3 D°~l + H20
CHmcnzcnzcnz —4———4~H> CH3CD(CH2)2D > CH3CD(CH2)ZD
1 1,2-H:~' OH XII
+ 0
CH3CHDCHCH2D > CH3CHDCH-CH2D
OH
XIII

Thereby giving at least small amounts of XII and XIII.

The study of the nmr and the mass Spectra of the secondary

butyl alcohols Showed no presence of XII or XIII, thus, ex-

cluding 1,3-hydride shifts. Since methyl cyclopropane
Compr ised only 0.6% of the total product in the deamination,
substituted methyl bridged cyclopropane and the edge pro-
ton ated cyclopropane could not be intervening to any ap-
Preciable extent in the rearrangement.

Thus, it appears that protonated cyclopropane intervenes
as an intermediate to a greater extent in the propyl system
but Vie ry little in higher homologues. The factor responsible
for decreasing stability of substituted protonated cyclo-
propane has been attributed to 1,2—eclipsing interactions

th .
at are present In such systems.

 

The present work is undertaken, with an aim to obtain
inf
c33";‘Il'tation regarding the Significance of intermediacy of

pro
torlated cyclopropanes in the deamination of B—pentylamine.

9
It is also intended to investigate if any 1,4—, 1,5—hydride
Shifts and/or alkyl Shifts to carbonium ions are occurring
as a result of the deamination.
Examples of hydride Shifts of higher order (1,4-, 1,5—,
1,6—) in noncyclic aliphatic system are very few. Most of
these are restricted to medium Size rings in which trans—
annular hydride shifts occur as Shown by independent dis—
coveries of Prelog (30) and COpe (31). Transannular
hydride shifts to carbonium ions in medium Size rings have
been observed in many reactions like hydroxylation of
olefins with performic acid, solvolysis of cycloalkyl
tosylates, and nitrous acid deamination of cycloalkylamines
(2323;)-
1,5-Hydride shifts are restricted also to rigid poly-
Cyclic molecules in which these reacting Sites are in close
proximity and favor the formation of a Six—membered cyclic
transition state. Winstein, e_t_ a; (33) have Shown that
1' 5‘1‘13/dride Shift was occurring in decahydrodimethano
naphthalene system. When XIV-OBIS was subjected to acetoly—

s .
ls ' )(V and XVI were obtained as the only products of the

reaction.
the

These were the hydrogen Shifted products. When
Shifting hydrogen in XIV-OBS was replaced by deuterium

an
E‘EDpreciable kinetic isotope effect was observed KH/KD =

1-24 . . . .
~ Also the rate of Ionization of XIV-OBS was greater

th
an that of the 7-norbornyl system by a factor of Slightly
mo
re than 103. All these observations were explained by

hyci
ngen participation in the ionization step of XIV.

H H

OBS

.XIV

XVII

 

AnOther compelling evidence in support of the above mechan-
ism was the absence of any ring contraction products like
XVII which are formed in solvolysis of 7-norbornyl deriva-
tives.

Some steroids undergo 1,5—hydride Shifts to give cor-

responding rearrangement PrOdUCtS (34) .

NaN02
aq HOAc

 

 

11

Many acid catalyzed 1,5-hydride shifts are known to

Occur in cyclic compounds. Letsinger and coworkers (35;

36) demonstrated a new example of 1,5—hydride Shifts in

perisubstituted naphthalene

H OH
H I
Q c’0\c ’¢ O‘/‘c/O\c H- oeHc:
H/C
—"'
0

gOH

H0-c-+ OCHs2 H0 C CH¢2 ,

l (37) have reported 1,5—hydride shift in the

C3311€1r1, et

f0 1 1 Owing case

+
I \ NZCHZ —‘¢ _N2 CH”¢ ' H20
'N NHCH2¢

"”"’ -CH2-® “CH29
0

+ G-CH + H

.Polyphosphoric acid has been used to catalyze the

is
(DrrLEErization (38) of various y—hydroxy olefins to satur-

at
ea ketones (equation (3))

12

PPA (3)

HO H R
CH3 R2

 

This isomerization has been rationalized by many con-
ceivable mechanisms such as (a) migration of the double
bond to the enolic position, (b) internal hydride transfer
of O—H hydrogen and (c) internal transfer of carbinol
(Z—Ii.

Hill and Carlson (39) have recently carried out poly-

PhOSphoric acid catalyzed isomerization of 2—deuterio-6-
methyl 5—en-2-ol(XVIII) to 6-deuterio 6-methyl heptanone-Z

(}CJ:XZ)

 

(CH3)2 D 0H (CH3)2C OCH3

XVIII XIX

'P . . . .
hey p01nted out that the transformation proceeded by intra-

m
O:Leczular 1,5-deuteride transfer by way of a cyclic mechan-

iSm

H+ > 1,5 D:~>
(c I 1 0.
Ha )2c D 0H (CH3)2C+ [OH (CH3)2C-D
CH3 CH3

XVIII XIX

 

 

13
Furthermore, when dextrorotatory isomer of 6-phenylhept
5-en-2—ol (xx) (a)D +16.9°, was isomerized under the same
reaction conditions, optically active 6-phenyl heptanone-2
(XXI) (a)D +2.3O was the product. The direction and degree
of the stereospecificity were determined by degrading
(XX) and (XXI) to compounds of known absolute configuration
(XXII) and (XXIII). Based on the maximum rotation reported
in the literature, it was concluded that the reaction pro-
ceeded with an optical purity of 15%. These observations
led to the postulation that a Six membered cyclic transi—
tion state was involved, since it would adopt a conforma-
tion resembling cyclohexane chair with the phenyl at C—6
and the methyl at C—2 occupying equitorial position,
consonant with their larger steric requirements than methyl

and hydroxyl respectively.

 

 

 

 

 

¢
¢
COCH
CH 3
CH3 3 XXI
S (+)
03 1.2 OH
i V
CH2CH2CHO CHZCHZCHZCOOH
HO‘j—H m-(sa
H3 CH3

5 (-) XXII s (+) XXIII

14

Karabatsos and coworkers (29) have revealed the fact
that in the deamination of deuterated gfbutylamines, 1-
butanol obtained as one of the products was less than 0.1%
isotOpically rearranged. On the basis of this result,
they have ruled out 1,4—hydride and 1,2—, 1,3-alkyl Shifts,
as well as protonated cycloprOpane, as the pathways to
1-butanol.

Karabatsos, Rickter and Meyerson (40) undertook the
study of deamination of 1-pentylamine-1,1fig2. The percent-
age of the products obtained in the deamination were as
shown on the following page. The mass Spectral analysis
of the trimethylsilyl derivative of the 1-pentanol product
Showed that there were actually a few percent of a-protons
in 1-pentanol, as shown on the following page. The distri-
bution of the deuterium in the secondary pentanols indicated
that there had been successive 1,2-hydride shifts down the
chain.

Earlier Streitwieser (41) had reported that, in the
deamination of geamyl amine, substantial amounts of 2-
pentanol were obtained but no 3-pentanol was observed. They
suggested that the 2—pentyl cation formed in the rearrange-
ment did not rearrange further. However, 3-pentanol was
one of the products observed by Karabatsos and Rickter in

the same reaction.

his fl.
_ u

3.01 V‘
U

a: '1
yuak

15

 

 

 

 

 

 

 

95
Normal-
ized
P -I
92.2% ‘g-C4H9CDZOH 95.0
2.8% 'g-C4H7D2CH20H 2.9
220 > 2.1% .Q-C4H8DCHDOH 2.1
2.9% ng4H9CHDOH
T _
CH3CH2CH2CH2CD2NH2
96.2% g2 89.8% E¢C3H7CHCHD2
I
._ OH
CH3CH2CH2CH2CHDNH2 140
> 6.3% ‘Q-C3H5D2CHCH3
3'8%-91 OH
3 .8% E-C3H7CHCH2D
U
_ OH
4% F’
> 96% C2H5CHCH2CHD2
0H
4% C2H5CHCH2CH2D
I
_ OH
19%
> Pentenes
9%
Other products (Pentyl
‘————*——> nitrites, Pentyl nitrates

and nitropentanes).

The purpose of the present work is to investigate in
detail, the question of 1,5-hydride Shift in the deamina-
tion of deuterated pentylamines. It is also aimed to gain

some knowledge about the Significance of protonated

1

16
cyc10propane intermediates in this reaction. If 1,5-
hydride shifts are occurring in the reaction, the deamina-
tion of deuterated 1-pentylamine would yield isotope-
position rearranged l-pentanol along with other products.

HNo2 +- 1,5 H: ~
NH2 HEI5:_> CH3CH2CH2CH2CD2 l

1H20 + _
CH2(CH2)3CD2H

 

CH3CH2CH2CH2CD2

CH3(CH2)3CD20H
l H20

HOCH2(CH2)3CD2H

Also, if 1,6—hydride Shifts should occur as the result
of deamination of 1—hexylamine, 1-hexylamine-1,1fid2 would,
on deamination, undergo the rearrangement according to the

following reaction sequence

HNo2 +
CH3CH2CH2CH2CH2CD2NH2 m> CH3CH2CH2CH2CH2CD2
11,6‘H:~ 1 H20
+
CHZCHZCHZCHZCHZCDZH CH2(CH2)4CD20H
1 H20

CH2(CH2)4CD2H
OH

The mass spectral analysis of the trimethylsilyl ether of
the alcohol products would be able to give information

about the isotopic distribution of the recovered alcohols.

RESULTS

Deamination of 1-pentylamines and 1—hexylamine was car—
ried out under the conditions used by Roberts and Halmann.
The normal alcohols and the mixture of secondary alcohol
products were collected by preparative gas chromatography.
Trimethylsilyl ethers of the alcohols were prepared, col-
lected, and subjected to mass Spectral analysis. ‘The data
for the mass Spectral analyses are given in Tables I - XXII.

In order to ascertain that the alcohol products are
formed irreversibly either from carbonium ions or their
immediate precursors, obtained from starting amine, 2-
pentanol, and 3-pentanol were separately subjected to de-
amination conditions. The product mixture on analysis by
vapor phase chromatography showed the alcohols to be pure
and unrearranged. Thus, 2-pentanol and 3-pentanol are ob-
tained as the result of the capture of rearranged carbonium
ions or their precursors, derived from starting amine, by
the solvent and not by their interconversion into each other

or from other products such as olefins.

1. 1-Pentylamine-1,1-_d_2

 

l-Pentanol

The mass spectral data for the trimethylsilyl ether
of unlabeled 1-pentanol and authentic 1-pentanol-1,1-§2 are
given in Tables I - II. The results of mass Spectral

17

18
analyses of the trimethylsilyl ethers of the recovered 1-
pentanol and of the mixture of 2-pentanol and 3-pentanol
from the demaination of 1-pentylamine-1,1-d2 are given in
Tables III and VIII, whereas those of unlabeled 2-pentanol,
3-pentanol, of authentic 2-pentanol-2-dl, and 3—pentanol-
3-g1 are given in Tables IV-VII.

In order to determine the isotopic composition of 1-
pentanol recovered from the deamination of 1-pentylamine-
1,1-g2, it is necessary to account for the rearrangement
occurring in the mass spectrometer and also for contributions
from Q; species in the reactant.

Trimethylsilyl ether of a known sample of 1—pentanol-
1,1-5;2 (Table II) gave (P-Me)+ 98.2% g2, 1.7% gl, 0.1%;1.0
and (p-Bu)+ 94.0% Q2, 3.3% g1, and 2.7% go. If it is as-
sumed that all deuteria are at C-1, then rearrangement in
the mass spectrometer has increased 1.6% Q1 and 2.6% do at
the expense of g2 Species in the parent less butyl ion.

Trimethylsilyl ether of the recovered 1-pentanol gave
(P-Me)+ 97.3% Q2, 2.0% gl, 0.7% g0, and (p-Me)+ 93.4% Q2,
3.6% g1, and 3% go (Table III) thereby resulting in the in—
crement of 1.6% g1 and 2.3% So at the expense of Q2 species
in the parent less butyl ion. This increment compares well
with that occurring in the authentic 1-pentanol-1,1—_g_2
nemely, 1.6% g1 and 2.6% d9. Thus.the 1-pentanol recovered
from the deamination of 1-pentylamine-1,1—§2 is almost com—
pletely isotope-position unrearranged. Therefore

HClO
CH3CH2CH2CH2CD2NH2 NaNo: > CH3CH2CH2CH2CD20H

100% g2 100%

 

19

Table I. Mass Spectrum of unlabeled CH3CH2CH2CH2CHZOSi(CH3)§

 

 

 

 

 

M/e Pk. Ht. Mono

149 0.3 .2

148 3.7 .6

147 46.0 .9

146 135.9 —2.6 P-leSS methyl
145 1068.0 1068.0 99.9% at mass 145
144 .2 .1

143 .9 .9 C7H17OSi+

2 1069.0 12.97, 4.22, 0.28

106 .7 .2

105 10.4 0.0

104 26.0 -.2 P—less Butyl
103 275.1 271.7 72.4% at mass 103
102 11.0 3.3

101 80.3 79.5 C4H11051+

100 2.7 .8

99 19.8 19.8 9.61, 3.86, 0.17

 

2 375.1

20

Table II. Mass spectrum of authentic CH3CHZCHZCH2002051(CH3)5

 

—.——v

 

 

 

 

 

 

 

 

 

 

M/e Pk. Ht. Mono
151 0.1 .05
150 3.2 0.0 P-leSS Methyl
149 48.5 .4 Mono Distribution
148 146.4 -2.0 1137.4 98.2%g2
147 1140.0 1137.4 99.9% 19.9 1.7%g_I
of Z
146 20.1 19.9 = 1158 0 .7 .1%g_0
145 1.5 1.4 1158 0
144 .5 .5
2 1159.2
107 10.6 .5 P-leSS Butyl
106 25.7 .3 Mono Distribution
105 263.1 259.2 259.2 94.0%512
104 17.0 9.0 9.0 3.3%g1
103 80.5 79.3 72.4% 7.4 2.7%‘9o
of z -——————
102 10.7 9.6 = 275.6 275.6
101 8.7 7.6
100 9.8 9.2
99 6.7 6.7
2 380.6

21

Table III. Mass spectrum of CH3CH2CH2CH2CHZOSi(CH3)5 from
1-pentanol obtained from the deamination of

l-pentylammonium perchlorate-1,1gd2

 

 

 

 

 

 

 

 

 

M/e Pk. Ht. Mono

150 5.3 .5

149 71.7 -1.4 P-less Methyl

148 225.0 -0.7 Mono Distribution
147 1734.- 1728.9 99 9% I72879 97.3% g2
146 36.3 34.4 §f1§76_5 34.4 2.0%;1
145 14.3 14.1 13.2 0.7% pg
144 .9 0.9 I77675‘

2 1778.3

108 .6 -.1 P-less Butyl
107 15.9 .6 Mono Distribution
106 38.1 -.8 _‘—_—'
105 402.0 395.7 72.1% 395.7 93.4%512
104 27.8 15.1 65.2 15.1 3.6% d1
103 127.8 125.9 = 423.7 12.9 3.0%_<i_1_0
102 17.0 15.3 ‘42377

101 13.8 12.1

100 14.4 13.4

99 10.1 10.1

 

03

Z 587.

22

 

 

 

 

 

 

 

Table Iv. Mass Spectrum of CH3CH20H20H(CH3)081(CH3)3
M/e Pk. Ht. Mono
150 .1 .03
149 .8 .1
148 3.7 .2
147 36.0 16.8 P-less Methyl
146 58.8 -.3
145 456.0 455.6 98.3% at mass 145
Jx44 2.0 1.1
143 6.9 6.9 C7H17OSi+
2 463.6 12.97, 4.22, 0.28
121 1 0.0
120 4.0 .9 P-less Propyl
119 67.4 -1.0
118 183.6 -.4
117 1710.— 1708.8 99.0% at mass 117
116 8.1 7.1
115 9.7 9.7 C5H130Si+
2 1725.6 10.75, 4.00, 0.18
133 .8
132 4.3
131 36.0
130 2.2
129 10.2
128 .3

Uh Qcarrected

253.8

 

23
Table v. Mass Spectrum of authentic CH3CH2CH2CD(CH3)OSi(CH3)3

¥

 

 

 

 

 

 

 

 

M/e Pk. Ht. Mono
149 1.2 1
148 13.8 -.1 P-less Methyl
147 45 .3 3 .7 Mono Distribution
146 320.0 319.6 98.3% 318.2 100% g1
145 2.8 2 7 of z
144 .6 .5 = 318.2
143 .9 .9
2 323.7
L21 2.3 .05
120 48.7 .6 P-less Propyl
1 1 9 130 .2 . 5 Mono Distribution
118 1203.0 1201.4 99.1% 1201.4 99.3% 91
117 13.6 13.1 of >3 8.7 .7% 51,0
116 4.0 3.7 = 1210.1 1210.1
115 2.3 2.2
114 .7 .7
2 1221.1
133 1.9
132 6.0
131 2.9
130 5.9
129 1.2

24

Table VI. 'MaSS Spectrum of unlabeled (CH3CH2)2CHOSi(CH3)§

 

 

 

 

 

 

 

 

 

 

 

jM/e Pk. Ht. Mono
149 .1 .1
148 .8 0.0
147 10.9 1.8 P-less Methyl
146 27.7 -.3
145 216.0 215.8 98.7% at mass 145
144 1.1 .8
143 2.1 2,1 071117031+
2 218.7 12.97, 4.22, 0.28
134 4.2 .2
133 67.6 -.9
132 196.8 -1.0 P—less -Ethyl
131 1669.— 1667.2 99.5% at mass 131
130 6.1 5.7
129 3.0 3.0 C6H15081+
2 1675.9 11.85, 4.11, 0.24
119 .3
118 1.2
117 11.1
116 14.7
115 36.4
114 .2
113 1.9
Uncorrected

2 65.8

25

Table VII. Mass Spectrum of authentic (CH3CH2)2CDOSi(CH3)3

 

 

 

 

 

 

 

 

 

 

M/e Pk. Ht. Mono
149 .7 .2
148 6.1 —.2 P—less Methyl
147 20.6 1.3 Mono Distribution
146 147.0 145.8 99.1% 145.8 94.1% d;
145 9.4 9.3 of 2 9.2 5.9% do
144 .6 .5 = 155'0 155.0
143 .8 .8

2 156.4
135 3.0 .3
134 45.3 .3 P-less Ethyl
133 132.3 .1 Mono Distribution

____1,

132 1098.0 1088.8 99.5% 1088.8 93.7% g1
131 77.0 76.8 of 2 73.3 6.3% d9
130 1.7 1.6 = 1162.1 1162.1
129 .7 .7

 

 

2 1167.9

26
Table VIII. Mass spectrum of CH3CHZCHZCH(CH3)OSi(CH3)5 and
(CH3CH2)2CHOS1(CH3)3 from the mixture of 2-
pentanol and 3-pentanol from the deamination

of 1-pentylammonium perchlorate-1,1-d2

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

M/e Pk. Ht. Mono
150 1.2 .2
149 14.8 .5 P—less Methyl
148 44.6 _42__ (Mono Distribution
147 343.0 338.1 2 = 430.9 338.1 78.5% d2
146 19.8 7.9 7.9 1.8% d1
145 91.8 91.8 84.9 19.7% go
144 .3 .3 . 430.9

2 438.1
136 .2 2
135 7.0 0.0 P—less Ethyl 3-amyl
134 20.8 0.0 ' 'Mono Distribution
133 178.2 170 7 99.5% 170.7 49.4% g2
132 24.5 4.3 of 2 4.3 1.3% d1
131 170.4 170.2 = 348.0 170.2 49.3% pp
130 1.2 .8 345.2
129 3.7 3.7

2 349 7
122 3.0 .6
121 52.6 -.9 P-less Propyl 2-amyl
120 142.8 -2.3 Mono Distribution
119 1344.- 1336.6 99.0 % 1336.6 91.8% d2
118 45.8 36.2 of 2 36.2 2.5% d1
117 89.0 88.4 = 1455.7 82.9 5.7% Q”
116 .9 3 3 1455.7
115 .8 5.8
114 .1 .1

 

 

 

27

Interpretation of the mass Spectral data for trimethyl-
silyl ethers of 2-pentanol and 3-pentanol is somewhat more
complex. It Should be noted that the trimethylsilyl ether
of 2-pentanol could lose both, the propyl group leavingean
ion of mass 117, and the methyl group leaving an ion of mass
145. Furthermore, it could lose methyl group by path a,
that is by the cleavage of Silicon—carbon bond, and by path

b, which is by the cleavage of carbon—carbon bond.

 

 

 

 

 

 

+
CH3CH2CH2CHCH3 CHCH3
I _ I
O propylgroup> O
l I
CH3~Si-CH3 Si(CH3)3
CH3 Mass 117
1
CH3CH2CH2CH CHacHZCHZCH-é CH3 CH3CH2CH2CHCH3
' b ' a l
O <— O a "5 O
I I I
CH3-Si-CH3 CH3-Si f-CH3 CH3-Si
CH CH CH
L 3 I _ 3 I L 3 J
Mass 145 Mass 145

On the other hand, the trimethylsilyl ether of 3-
pentanol could fragment both by the loss of methyl group
leaving an ion of mass 145, and by the loss of ethyl group
when an ion of mass 131 will result.

The values for the mixture of trimethylsilyl ethers
of 2—pentanol and 3-pentanol obtained from the deamination
of 1-pentylamine-1,1-g2 (98% Q2 and 2% d1) are given in

Table VIII.

28

2-Pentanol

 

The isotopic composition of 2-pentanol product can be
determined from the isotopic distribution of parent less
methyl and parent less propyl ions of (P-CH3)+ 78.5% d2,

+
1.8% d; and 19.7% do, and (P-Pr) 91.8% Q2, 2.5% d; and

 

5.7% g” respectively. (P-CH3)+ ion arising from cleavage

. 19.7 +
of carbon-carbon bond is 21.3% (98.0 _ 5.7 x 100). (P-Pr)
gives 91.8% g2 which means that it is 93.6% (géég-x 100)

unrearranged. Since starting amine is 2.0% 91' it will con-
tribute about 1.9% g1 and 0.1% do to the (P-Pr)+ of the
ether. Thus, the isotopic composition of 2-pentanol, which
arises solely from 1-pentylamine-1,1fid2 (98%) is 91.8% d2,
0.6% g1, and 5.6% go. 0.6% Q1 is probably the result of
some rearrangement occurring in the mass Spectrometer.
Dropping 0.6% $1 and normalizing, then, gives the follow-

ing results:

CH3CH2CH2CH2CD2NH2 _'_> CH3 CH2CH2CHCHD2 + CH3CHCH2CH2 CHDZ
I I
OH OH

100% d2 94.2% 5.8%
1 2

3-Pentanol

The isotopic composition of 3—pentanol can be obtained
from parent leSS ethyl ion which has the composition 49.4%
g2, 1.3% g1 and 49.3% 90' The trimethylsilyl ether of the
3-pentanol-1,1—gz can lose either C2H3D2 or C2H5 with equal
probability. If one assumes successive 1,2-hydride Shifts

occurring as a result of the deamination, then, the ether

29
of 3-pentanol-l,1-d__2 recovered from the deamination of 1-
pentylamine-1,1-g2 (98% Q2, 2.0% gl) Should give the
+
values for (P-Et) as 49% g2, 1.0% g1, and 50% go. The
actual isotopic composition of the parent less ethyl ion
of the ether (49.4% Q2, 1.3% Q1 and 49.3% do) agrees well

with the calculated values, considering possible rearrange-

 

ment occurring in the mass Spectrometer. Thus,
CH3CH2CH2CH2CD2NH2 > CH3CH2CHCH2CHD2
I
OH
100% g2 100%

2. 1—Pentylamine-2,2-d2

 

The mass Spectral data for trimethylsilyl ethers of
the alochols obtained from the deamination of 1-pentyl-
amine-2,2-g2 (96.7% £2 and 3.3% Q1), are given in Tables X

and XI.

1—Pentanol

 

Comparing the data for trimethylsilyl ether of the
authentic 1-pentanol-2,2—§2 (Table IX) with that of the
recovered 1-pentanol (Table X), and taking into account the
rearrangement occurring in the mass Spectrometer Shows 1-
pentanol to be almost, not all, isotOpe position rearranged.

Thus,

 

CH3CH2CH2CD2CH2NH2 > CH3CH2CH2CDZCH20H

100%

30

2-Pentanol

 

Correcting the values for (P-Pr)+ ion in Table XI for
contribution from g1 Species in the reactant and normaliz—
ing for 100% isotopic purity gives the following isotopic

composition of the recovered 2-pentanol.

 

CH3CH2CH2CD2CH2NH2 > CH3CH2CH2CDCH2D + C3H6DCHCH§D +
I I
OH OH
100% g2 94% 1.6%
3 4
CH3CHCH2CHDCH2D
I
OH
4.4%
5

3—Pentanol

On the basis of successive 1,2—hydride shifts which
would result in the formation of 3-pentanol-1,2-§2 from
the deamination of l-pentylamine-2,21d2 (96.7% g2 and 3.3%
d1), the isotopic composition of (P—Et)+ ion would,thus,be
predicted to be 48.3% g2, 1.7% g1, and 50.0% go. The
observed isotopic distribution for the same ion in Table XI
(50.4% g2, 1.9% Q1, and 47.7% 90) Shows d2 Species to be
about 2% higher than the predicted value, with the cor-
reSponding decrease in the value for Q” Species. This dif-
ference connot be accounted for, satisfactorily, in absence
of the mass Spectral data for the authentic 3-pentanol—1,2-d2.

However, it can be seen that more than 98% of recovered 3-

pentanol is 3-pentanol—1,2-g2.

31

 

 

Table IX. Mass Spectrum of authentic CH3CH2CH2CD2CHZOSi(CH3)3
M/e Pk. Ht. Mono
150 9.1 .8
149 120.- 4.7 P—less Methyl
148 355 -1.5 Mono Distribution
147 2736. 2726.9 99.9% 2726.9 97.3%{g2
146 68. 66.7 of 2 66.7 2.4% pl
145 9.5 9.4 = 2801.2 7.6 0.3% 510
144 1. 1. 2801.2
2 2804.0
P-leSS Butyl
106 2.5 1 Mono Distribution
105 37. 7:3 71% l 7.3 1.2%g2
104 83.5 11.1' of 2 11.1 1.8%g_1
103 744. 739.3 3 607.7 589.3 97.0% do
102 36.8 32.1 607.7
101 43.4 41.4
100 19.4 18.8
99 5.9 5.9

 

 

 

 

 

 

 

 

 

 

2 855.9

 

 

32

 

 

 

 

 

 

 

 

 

 

 

Table X. Mass spectrum of CH3CH2CH2CH2CH20S1(CH3)3 from
1—pentanol obtained from the deamination of
l—pentylammonium perchlorate-2,2-d2

M/e Pk. Ht. Mono

150 9.1 .7

149 125.1 1.3 P—less Methyl

148 38.1 -2.8 Mono Distribution

147 2940. 2926.7 99.9% 2926.7 96.5%_d_2

146 101.1 99.9 of 2 99.9 3.3% a,

145 8.8 8.7 = 3033.3 6.7 0.2% 510

144 1.0 1.0 3033.3

2 3036.3
P—less Butyl

106 3.0 .4 Mono Distribution

105 40.7 8.5 71.0% 8.5 1.3% g2

104 90.3 11.8 of 2 11.8 1.8% pl

103 807. 801.8 = 661.0 640.7 96.9% 910

102 41.3 36.2 661.0

101 47.0 44.7

100 21.7 21.0

99 7.0 7.0

 

 

33
Table XI. Mass Spectrum of CH3CH2CH2CH(CH3)OS1(CH3)5 and
(CH3CH2)2CHOSi(CH3)3 from the mixture of 2-
pentanol and 3—pentanol obtained from the deam-

ination of 1-pentylammonium perchlorate-2,25d2

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

M/e Pk. Ht. Mono
150 1.8 .4
149 21.8 .4 Pwless Methyl
148 70.0 -.8 Mono Distribution
147 516.0 495.4 98.7%* 495.4 76.1% g2
146 158.1 157.4 of 2 155.8 23.9%g1
145 5.1 4.8 = 651.2 651.2
144 2.2 2.2

2 775.0 2 659 8
136 0.8 4
135 6.4 —.2 P—leSS Ethyl 3-amyl
134 19.8 _;l__ Mono Distribution
133 168.0 161.0 99.5% 161.0 50.4% g2
132 24.4 6.0 of z 6.0 1.9%91
131 153.3 152.2 = 327.2 152.2 47.7% go
130 8.1 8.0 319.2
129 1.0 9
128 .7 7

2 382.5 2 328 8
122 4.6~ .8
121 82.9 -1.0 P-less Propyl 2-amyl
120 225.0 -4.5 Mono Distribution
119 2109.0 2093.0 99.0% 1093.0 90.9%g2
118 120.0 107.0 of 2 107.9 4.7%g_1
117 111.0 110.0 = 2302.2 _ 101.3 4.4%_d_0
116 8.3 7.7 2302.2
115 5.3 5.2
114 1.0 9 *2-amy1 contributes 98.3%
113 0'8 8 3-amyl EgnéfIHEg $199.1%

 

 

 

2 2667.9 22325.5 t0 (P-Me) ion

34

 

CH3CH2CH2CD2CH2NH2 > CH3CH2CHCHDCH2D
OH
100% QZ > 98%

3. 1-Pentylamine-3,3-§2

 

Tables XIII and XIV give the mass Spectral data for
the trimethylsilyl ethers of l-pentanol and the mixture of
2-pentanol and 3-pentanol, obtained from the deamination of

1-pentylamine—3,3-g2 (98% g2 and 2.0% d1).

1-Péntanol

 

Treatment of the data for the silyl ether of authentic
1—pentanol—3,3-d2 (Table XII) and of that of the ether of
the recovered 1-pentanol in the manner similar to that for
the above labeled l-pentylamines, demonstrates that the 1—

pentanol product has the same isotopic composition as the

 

starting amine. Thus,
CH3CH2CD2CH2CH2NH2 > CH3CH2CD2CH2CH20H
100% g2 100%

2—Pentanol

 

The values for (P—Pr)+ ion from Table XIV are 1%511
and 99% d9. After taking into consideration the contri-
bution from £1 Species in the reactant, and normalizing to
100% iostopic purity, the data can be accommodated by the

following isotOpic composition of 2-pentanol product:

.1

 

.4.»

35

Table XII. Mass Spectrum of authentic CH3CH2CD2CH2CHZOSI(CH3)3

 

 

 

 

 

 

 

 

 

 

 

 

M/e Pk. Ht. Mono
150 4.0 -.1
149 62.0 -.5 P-less Methyl
148 191.1 -2.2 Mono Distribution
147 1485.- 1480.8 99.9% 1480.8 97.6%912
146 31.0 29.9 of 2 29.9 2.0%-g1
145 8.1 8.1 = 1517.5 6.8 0.4% pg
144 .2 .2 1517.5
2 1519.0
P-leSS Butyl
106 .9 .04 Mono Distribution
105 17.6 1.1 1.1 0.3%g_2
104 42.2 .8 .8 0.2%31
103 427.0 424.2 71.1% 351.3 99.5% go
102 18.6 14.7 of 2 353.3
101 37.8 36.8 = 353.2
100 8.8 8.4
99 3.9 3.9

 

 

2 489.9

Table XIII.

36

Mass Spectrum of CH3CH2CH2CH2CHZOSi(CH3)§ from

1-pentanol obtained from the deamination of

l-pentylammonium perchlorate-3,3-g2

 

 

 

 

 

 

 

 

 

 

 

 

M/e Pk. Ht. Mono
151 .1 .06
150 5.1 P-less Methyl
149 72.4 -.5 Mono Distribution
148 224.1 —1.3
147 1731.— 1726.3 99.9% 1726.3 97.9% g2
146 35.3 34.9 of 2 34.9 2.0%g_1
145 2.9 2.9 = 1762.6 1.4 0.1%-gO
144 .3 .3 1762.6
2 1764.4
P-less Butyl
106 1.0 0.0 Mono Distribution
105 20.3 .2 72.1% 1.2 0.3% g2
104 49.3 .5 of z 1.5 0.4%511
103 493.0 489.8 = 407.4 404.7 99.3%;1O
102 21.2 16.7 407.4
101 43.6 42.5
100 .9 9.5
99 3.9 3.9

 

 

37
Table XIV. Mass Spectrum of CHacHZCHZCH(CH3)osi(CH3)5 and
(CH3CH2)2CHOSi(CH3)3 from the mixture of 2-
pentanol and 3-pentanol Obtained from the deam-

ination of 1-pentylammonium perchlorate-3,3-g2

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

M/e Pk. Ht. Mono
150 1.0 -.3
149 18.8 .3 P—less Methyl
148 56.8 —.5 * Mono Distribution
147 440.— 438.6 98.7% 438.6 98.5% 912
146 10.1 9.8 of 2 6.6 1.5% d1
145 2.0 1.9 = 445.2 445.2
144 .8 .8

2 451.1
135 6.3 0.0 P-less Ethyl 3-amyl
134 22.3 -.8 Mono Distribution
133 162.0 144.4 99.5% 144.4 48.2% g3
132 145.8 144.5 of 2 144.5 48.3% d1
131 11.0 10.9 = 299.3 10.4 3.5% go
130 .9 .9 299.3
129 .1 .1

2 300.8
120 3.2 .1 P-leSS Propyl 2-amyl
119 57.2 —.8 Mono Distribution
118 116.2 14.0 99.0% 14.0 1.0% gl
117 1413.- 1411.9 of 2 1409.9 99.0%-gO
116 9.8 9.6 = 1423.9 1423.9
115 2.2 2.2
114 .3 .3
113 .3 .3

21438.3

7 + .
*2—amyl contributes 98.3% to P-Me)+ ion
3—amyl contributes 99.1% to P—Me) ion

38

Table XV. Results of mass Spectral analysis of the tri-
methylsilyl ethers of authentic labeled alcohols

 

Ether (P-Me) (P—Bu)+ (P—Pr)+ (P-Et)+

% % % 95

 

Authentic 98.2 g2 94.0 g2
CH3CH2CH2CH2CD20S1(CH3)3 1.7 d1 3.3 91

0.1 dO 2.7 do

Authentic 97.3 g2 1.2

LE1:

CH3CH2CH2CD2CHZOSi(CH3)3 2.4 d1 1.8g1

0.3 do 97.0g0

Authentic 97.6 g2 0.3 92

CH3CH2CD2CH2CHZOSI(CH3)3 2.0 Q; 0.2g1

Authentic 100.0 d1 99.3 d1
CH3CH2CH2CD(CH3)OSi(CH3)3 0.7 an
Authentic 94.1 g1 93.7 91

(CH3CH2)2CDOSi(CH3)3 5.9 d0 6.3 610

39

 

 

ac Tm at odd as Tee 68 To
am.m.we Hm.o.H am.m.a am e.o em c.m umznmoamoncoamoamo
am «.2. am 9mm am me 9m 6.3 Scum
am has am «is em men em «.6
am.m.a am.8.s Hm.m.mm am w.H am m.m nmznmonnoamonmoamo
am Ton am med am fies «m m4 am p.68 Sena
em m2. am an cm 6.3 em on am To
am.m.H Hm.m.m am.w.H Hm.o.m am o.m nmznoonmonmoamonmo
am eds am 828 am has «M 3.8 mm «.8 Sons
e e , e e e

Aumumo Aumumv Amsrmv Asmumv Aozrmv

+ + + + + oases

aflnmooamomodAamoamov + «Aamooamofiamovmonmodmonmov «AmmovamONTUNmonmonmommo

 

maosooam 0:» mo mumsum Ahaamamsumfiflnu m0 mammamcm Hmuuommm mmmE m0 muasmmm

mgmuoasouom ESHSOEEmamDSTQIH ooaonma mo coagmcflfimmo map Eonm Umcfimuno

. H>X OHQMB

 

I.
n he
I‘d

.6

11%

r}.

I. .
3%

40

 

CH3CH2CD2CH2CH2NH2 > CH3CH2CD3CHCH3 + CH3CHCDHCHDCH3
I I I
0H OH

100% 22 6 7

 

99%

+ CH3H6D-CD-CH3
I
OH

8
1%
The alcohols 6 and 7 would contribute to 90
Species in (P-Pr)+ ion, whereas, alcohol 8 would contri-

bute to $1 species in the same ion.

3-Pentanol

 

The starting 1-pentylamine—3,3:§2 (98% d2, 2.0% 91)
would, assuming successive 1,2-hydride Shifts, lead to
3-pentanol-2,3-g2 (98%). The latter would then contribute,
about, 49% to 92 Species and 49% to d; Species in
)+

(P-Et ion. However, in the case of 1-pentylamine-3jd1

k
(2% 91): an isotope effect of about EE- 2:2 would be
exhibited as a result of intramolecular 1,2-hydride Shift,

which would result in 3-pentanol obtained from 1-pentyl-

amine-3-gl, having approximately the following composition:

 

CH3CH2CHDCH2CH2NH2 > CH3CH2CDCH2CH3 + CH3CH2CHCHDCH3
6m 5m
2%.91 1.4% 0.6%
9 10

Both alcohols 9 and 10 would, then, together contribute,

roughly, 1.7% to dl species and 0.3% to g” Species in

41
+ . . . . . .
(P-Et) ion in Table XIV. Thus, overall isotopic distribu-
+
)

tion of (P-Et ion would be predicted to be, about 49% d2,

50.7%‘Q1, and 0.3% g9. Inspection of the values for (P-Et)+
ion in Table XIV (48.2% g2, 48°3%.§1I and 3.3% do) Shows
that the actual distribution is different by g9 being about
3.0% higher than the predicted value. This results in a
corresponding decrease in the values for d2 and .91 Species.
InSpection of the mass Spectral data for authentic 3-pen—
tanol-3-gl (Table VII) demonstrates that only about 0.4%
can be attributed, as an upper limit, to the rearrangement
occurring in the mass Spectrometer. The duplicate run on
1-pentylamine-3,3-§2, also,shows the predicted isotOpe
distribution for the same ion, by Q” being about 4.5%
higher than the predicted value.

Since the mass Spectral data for trimethylsilyl ether
of 3-pentanol-2,3-§2 iS not available, no definite conclu-
sion can be drawn to expalin the observed difference in the
values. It is likely, that some unexpected fragmentation is

occurring in the mass spectrometer to cause this anomalous

data.

4. 1-Hexylamine-1,1-_g2

 

The mass spectral data for the trimethylsilyl ethers
of unlabeled 1-hexanol, authentic 1-hexanol-1,1—d , unlabeled
2-hexanol and unlabeled 3-hexanol are given in Tables XVII-
XVIII, XX, and XXI. Whereas,those for the alcohols recovered
from the deamination of 1-hexylamine-1,1-g2 (97.1% g2 and

2.9% gl) are given in Tables XIX and XXII.

42

 

 

 

 

 

 

 

 

 

Table XVII. Mass Spectrum of unlabeled
CH3CH2CH2CH2CH2CH20Si(CH3)3

M/e Pk. Ht. Mono

163 .2 .1

162 5.2 .3

161 64.1 0.0

160 204.9 —1.8 P—less Methyl

159 1467.0 1467. 99.9% at mass 159

158 .3 .1 csnlgosi+

157 1.3 1.3 14.09, 4.37, 0.33
2 1468.4

106 .8 .1

105 15.0 .4

104 36.3 .2 P-less Amyl

103 377.0 373.0 75.8% at mass 103

102 12.2 3.7 C4H11081+

101 87.0 85.6 9.61, 3.86, 0.17

100 4.1 1.1

99 28.9 28.9
2 492.3

150 .2

149 2.8

148 4.3

147 27.3

146 .2

145 2.4

144 1.3

143 9.2

Conc. HMDS = 0.69 volume %

43

Table XVIII. Mass Spectrum of authentic
CH3CH2CH2CH2CH2CDZOSi(CH3)3

 

 

 

 

 

 

 

 

 

 

M/e Pk. Ht. Mono
165 .1 .1
164 5.4 .2
163 69.0 -.3 P-less Methyl
162 224.1 0.0 Mono Distribution
161 1587.0 1583 .2 99 .9% 1583.2 98 .2% d2
160 26.3 25.6 of 2 25.6 1.6% $1
159 4.6 4.5 = 1612.2 3.4 .2%g_O
158 .5 .5 1612.2
2 1613.8
108 .7 0.0
107 14.5 .3 P-less Amyl
106 35.9 .2 Mono Distribution
105 370.0 365.5 75.8% 365.5 95.4% d2
104 19.0 10.5 of 2 10.5 2.7% g;
103 83.0 81.0 = 383.2 7.2 1-9%.Qo
102 16.0 14.6 383.2
101 9.7 7.9
100 10.0 8.1
99 17.9 17.9
2 505.5
150 .2
149 2 .3'
148 4.4
147 30.2
146 1.9
145 11.2

Conc. HMDS = 0.77 Volume %

44

 

 

 

 

 

 

 

 

 

 

 

 

 

Table XIX. Mass Spectrum of CH3CH2CH2CH2CH2CH20S1(CH3)5
from 1-hexanol obtained from the deamination
of 1—hexylammonium perchlorate-1,1—dz

M/e Pk. Ht. Mono

165 .1 .1

164 5.2 0.0

163 69.0 -.4 P-less Methyl

162 225.3 ._;1_ Mono Distribution

161 1590.0 1583.1 99.9% 1583.1 97.0% g2

160 48.5 48.1 of 2 48.1 2.9% Q1

159 2.8 2.7 = 1632.8 1.6 0°1%.§0

158 .5 .5 1632.8

2 1634.4

108 .6 0.0

107 14.4 .3 P-less Amyl

106 35.5 -.4 Mono Distribution

105 369.0 264.2 75.8% 364.2 93.9% fig

104 24.8 16.4 of 2 16.4 4.2% d1

103 83.0 81.1 = 387.9 7.3 1.9% g9

102 17.0 15.8 387.9

101 9.4 7.8

100 10.1 8.3

99 18.2 18.2
2 511.8

150 .2

149 1.0

148 .8

147 6.9

146 1.8

145 10.1

144 .5

Conc. HMDS = 0.18 Volume %

45

 

 

 

 

 

 

 

 

 

Table XX. Mass spectrum of CH3CHZCHZCHZCH(CH3)OSi(CH3)3
M/e Pk. Ht. Mono
163 .1 .1
162 1.3 0.0
161 17.1 -.4 P-less Methyl
160 55.2 -1.2
159 400.0 399.9 99.9% at mass 159
158 .3 2 C8H19031+
157 4 .4 14.09, 4.37, 0.33
2 400.5
120 4.4 .7
119 80.2 -1.6
118 213.0 -7.3 ‘ P-less Butyl
117 2049.0 2045.6 96.5% at mass 117
116 14.9 8.3 051113051+
115 61.3 61.1 10.75, 4.00, 0.18
114 1.0 .6
113 3.8 .8
112 .2 .1
111 .7 .7
2 2120.2
Conc. HMDS = 0.11 Volume %

46

Table XXI. Mass spectrum of CH3CH2CH2CH(CH2CH3)OSi(CHp)3

 

 

 

 

 

 

 

 

 

 

 

 

M/e Pk. Ht. Mono

162 .4 —.2

161 7.8 -.2

160 25.2 -.6 P-less Methyl

159 183.0 182.9 98.9% at mass 159

158 .6 .4 08H190Si+

157 11.7 1.7 14.09, 4.37, 0.33
2 185.0

149 .3 .3

148 2.2 -.3

147 36.3 .3

146 110.7 0.0 P—leSS Ethyl

145 853.0 852.5 99.3% at mass 145

144 3.1 2.7 C7H17OSi+

143 3.1 3.1 12.97, 4.22, 0.28
2 858.3

134 2.4 —.1

133 43.1 -.4

132 126.0 3 P-leSS Propyl

131 1059.0 1057.5 97.8% at mass 131

130 9.2 7.3 C6H15OSi+

129 15.8 15.8 11.58, 4.11, 0.24

128 .1 .1

127 .4 .4

L

 

 

2 1081.1

47

Table XXII. Mass spectrum of the trimethylsilyl ethers of

the mixture of 2-hexanol and 3-hexanol obtained
from the deamination of 1-hexylammonium per-

chlorate-1,1-g2

 

 

 

 

 

M/e Pk . Ht . Mono

164 .8 -.1

163 12.0 .1 P-less Methyl 2—hexyl
162 38.9 .5 Mono Distribution
161 273.3 268.8 99.9% 268.8 75.5% Q2

160 18.4 7.1 of 2 7.1 2.0% Q1

159 80.1 80.1 = 355.8 79.9 22.5% do

158 .2 .2 355.8

150
149
148

147
146
145

144
143

 

 

 

 

Poly 2 423.7 2 356.2

 

 

 

 

.2 0.0
1.9 0.1 P-less Ethyl 3-hexyl
4.1 0.0 Mono Distribution
32.4 5.7 99.3% 5.7 4.1% 92
18.3 1.1 of 2 1.1 0.8% gl
132.3 132.2 = 139.8 132.2 95.1% do
.7 .6 139.0
1.1 1.1

 

 

 

poly 2 191.0 2 140.8

119

Table XXII (Cont . )

48

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

M/e Pk. Ht. Mono
136 3 -.1
135 6.8 0 0 P-less Propyl 3-hexy1
134 20.0 - 2 Mono Distribution
133 168.0 166 5 97.8% 166.5 93.6%g2
132 9.2 8 7 of 2 8.7 4.9% 51.1
131 4.0 2 6 = 180.4 2.6 1.5% Q”
130 2.0 1.4 177.8
129 5.1 5.1
128 .2 .2

2 215.6 2 184.5
122 3.6 .6
121 65.5 —.3 P—less Butyl 2-hexyl
120 179.1 .4 Mono Distribution
119 1650.0 1642.7 96.5% 1642.7 97.1% g2
118 55.2 50.0 of 2 48.6 2.9% gl
117 47.0 45.8 = 1691.3 1691.3
116 7.1 6.3
115 6.5 6.2
114 .6 .5
113 1.2 1.1

2 1752.6

Conc. HMDS = 0.53 Volume %

49

1-Hexanol

The isotopic distribution of the trimethylsilyl ether
of the recovered 1-hexanol (Table XXI) was compared with
that of the authentic 1-hexanol-1,17Q2, and after taking
into account the rearrangements occurring during fragmenta—
tion in the mass spectrometer, it was found that the 1-
hexanol obtained from the deamination is not isotope-posi-

tion rearranged. Thus,

 

CH3CH2CH2CH2CH2CD2NH2 > CH3CH2CH2CH2CH2CD20H

100% g2 100%

In order to determine the isotopic composition of 2-
hexanol and 3-hexanol, it should be noted that the trimethyl-
silyl ether of 2-hexanol could lose both the methyl group
and the butyl group leaving ions of masses 159 and 117, re-
spectively. Also the methyl group could be lost both by
cleavage of Silicon—carbon bond (path a) and by cleavage of

carbon-carbon bond (path b)

+
b CH3
CH3CH2CH2CH2 4-CH’5-CH3 éggfigi> CHz-O-Si-CHs
0 a CH3
-Si H3}.CH3 Mass 117
Path/;////H \\\\\\E::: b
+ _ _ +
EHacHZCHZCHZCHCH3 CH3CH2CH2CH2CH
I I
O O
I I
CH3-Si CH3-Si-CH3
I I
CH3 J CH3 ‘-

 

 

 

 

h—Mass 159 “’Mass 159

50

2-Hexanol

 

The values for the (P-Me)+ and (P-Bu)+ ions for the
mixture of trimethylsilyl ethers of 2-hexanol and 3-hexanol
(Table xxn) are (P-Me)+ - 75.5% $2, 2.0% 31, and 22.5% go
and (P-Bu)+ - 97.1%'g2 and 2.9%‘d1. Since the starting
amine is 97.1%‘g2 and 2.9%'d1, it can be seen from the iso-
topic distribution of (P-Bu)+ ion that the isotopic composi-

tion of the recovered 2-hexanol is the result of a simple

1,2-hydride shift. Thus,

CH3 (CH2 )4CD2NH2 ———> CH3CH2CH2CH2CHCD2H
I
OH
100% 912 100%

Also, the isotopic distribution of the (P-Me)+ ion

shows that about 23.1%(%%4% x 100) of the methyl group is

lost by cleavage of carbon-carbon bond.

3-Hexanol

The trimethylsilyl ether of 3-hexanol could fragment by
losing methyl (path c), ethyl (path d) and propyl groups
(path e) leaving ions of masses 159, 145, and 131, respec-
tively.

e d
CH3CH2CH2 {- CH % CH2CH3
<3 c
CH3 - si -2- CH3
éng

The isotopic composition of the 3-hexanol product from

the deamination of 1-hexylamine—1,15§2 (97.1%.g2 and 2.9%.d1)

51
+
>

can be obtained from (P—Et and (P-Pr)+ ions. The values

for these ions from Table XXII are (P-Et)+ 4.1%‘g2, 0.8%
g1, and 95.1% 510 and (P-Pr)+ 93.6% 51., 4.9% g1, and 1.5% g0
Correcting the (P-Et)+ ion for contribution from $1 species
in the reactant and normalizing to 100% isotopic purity

gives the following result:

 

CH3(CH2)3CH2CD2NH2 > CH3CH2CH2CHCH2CHD2 +

OH
100%.g2 95.8% .ll
CH3CH2CHCH2CH2CHD2
OH
4.2% .;g

The values for the (P—Pr)+ ion would then be predicted
to be approximately 93.0% g2, 2°1%.QJI and 4.9%.d9, whereas,
the observed distributions for this ion are interchanged in
their values for Q; and g0. No plausible explanation can
be offered for this observed result.

The precentage compositions of the 2-pentanol, 2-hex—
anol, and 3-hexanol products from the deamination of labeled
1-pentyl— and 1-hexylamines respectively are summarized in
Table XXIII, whereas, those of the secondary alcohols to-
gether are given in Table XXVI.

The percentage compositions of the 2-pentanol and the
3-pentanol in the product mixture were determined by vapor
phase chromatography of the mixture from 20' x 1/4", 20%
Carbowax 20M on 60/80 chromosorb W column at 62°C and 50

psig, their retention times being 45 and 41 minutes, respec-

tively.

52
However it was not possible to collect the two alcohols
separately as the peaks overlapped, when larger quantities
of the mixture were injected.
The percentage composition of the 2-hexanol and the
3-hexanol in the product mixture was also determined in
the same manner from 20' x 1/4", 20% CarbOwax 20M on 60/80

chromosorb W column at 112°C and 30 psig.

53

mm as
Rm.v Rm.mm mooa
no mo mo

. u .
«omoamoumomoumommo + «omommomoumoamommo «amoroumoamoumonmo

 

 

Hosmxmnlm

 

mm mo0H

«mzuooumoumoumoumommo

 

.m .M m..
RH r! .uxmm .. «m.ecofi
mo \ mo mo /
. . -
mmooooammo + mmoomoomomommo + mmomoaooumommo amzumoumouoonmommo
m. w. .m
Ro.fi ev.¢ Ram «m moOH
mo mo mo
- . . .
oumomoommmo + oumoomoumomommo + ommooonmommommo «mammouooumoumommo
m. .w
um.m em.vm «m.uoofl
mo mo
. -
unmoumoamomonmo + nomomoamoumommo «mzaooumoumoamommo
mGOflufimomEoo mmmucmonmm mCAE¢

 

>Hw>wuommmmu
mmGHEmahmeIH can Iamucmmlfi vmamnma mo soaumcflsmmo map Eoum vmcflmuno
muosnonm Hocmxmplm;pcm Hocmxmalm .Hocmucmmlm 0:“ mo mCOHuflmomEoo mmmucmoumm .HHHNx magma

54

¥®.o mo

 

 

«amoumoumomoamommo
s 3 mg: mp Tam mo new «much:
.
+ Nomoamomoumonmonmo «amoroumoamoumommo umzuooumoamoumoumonmo
mo m.o
-
v.mw "mooooommo +
m.mm
®.m.fi ®.mu.n Emu Emu Emu NW KOCH
m"53.38«aroma mmoomoomomommo + «monouooamommo «mzumoumouooumonmo
mo m.H
-
N m m
m.ow o momoo m o +
m.mH m.mH mm .-m.m mm mo s.m> «m.mooa
ammoomomommonmo camoomoumomonmo + oumooommoumommo «mZNmoaooamommommo
m.wH m.ma mm m.Hm s.w mm mm w.ms «m moofi
uncommomoumonmo uncommoamomommo + muoomoumonmommo «mzuooamoumoumonmo
& Hocmxmnlm . .
Hmuoe pcm maocmucmmnm mmoa mHosmxmnlm cam maocmucmmlm
mo coaufimomeou R H mo mcowuamomfioo R mcfifid

 

mwcflEmH»Xm£IH can Iamuammla pmamnma mo coaumGHEmmU

map Eoum omcflmuno maonooam anmpcoumm may mo mGOHuHmomEoo mmmucmoumm .>Hxx manna

DISCUSSION

1. Normal Alcohols

The results show that the l-pentanol product obtained
from the deamination of the three labeled 1-pentylamines,
is recovered almost completely isotOpe position unrearranged.
From this observation it is concluded that all the mechanisms
involving rearrangements of the carbonium ion intermediate
by 1,3-ethyl shift, 1,4-ethyl shift or 1,5-hydride shift
may be discounted (equations 1-3). Also, any bridged sym—
metrical intermediate (1) and any equilibrating protonated
cyclopropane intermediates (II), (II'), (11"), with sub-

sequent formation of 1-pentanol may be discarded.

+
> CHZCHZCDZCHZCHZ

1 H20
HOCH2CH2CD2CH2CH3 (1)

+ 1 4-Me-AI +
CH3CH2CH2CH2 CD2 I . > CH2CH2CH2CD2CH3

1 H20
HOCHZCH2CH2CD2CH3 (2)

1,3-Eit:~

 

I ’H\ \
/ \
cfi2 + ‘Cf:::cH2
——CH 2 —>
\c

H2 (3)

 

1,5-H:~>

+ H20
CHZCHZCHZCHZCDZH

 

> Hocnzcnzcnzcnzcnza

55

CH3
I
CH2
I
H20 /’:§2
/ \\ H20
CH3CH2CH2CD2CH20H “\// \/ _> CH3CH2CH2CH2CD20H
2 ------- 2
(I)
CHZCHa CHZCHa CHZCHa CHZCHs
I I
-«”/CH <— £1“\H /CH2
H+,’ -> \
’1’ \\+ /
6H2-—-——CD2 CH2-————CD2 on ----- D2 CH ----- HD
\ /I
‘ + ’/ +/
‘H/ \\U
(11') (II) (11") (II"')
(H20 leo ino leo
CH3CH3CH2CD2CH20H CH3CH2CH2CH2CD20H
CH3CH2CH2CH2CD20H CH3CH2CH2CHDCHDOH

Similarly, the results show that the l-hexanol pro-
duct from the deamination of 1-hexylamine-1,1-§2 is iso-
tope position unrearranged. Such an observation makes it
possible to rule out any rearrangement occurring by 1,6-hy-
dride or any alkyl shifts like 1,3-pr0pyl, 1,4-ethyl and

1,5-methyl (equations 4-7).

/H+-CD ——CH
+ 2
1 6 'H 3 N I, >H2

 

 

CH3CH2CH2CH2CH2CD2 <#L* > -—-9
CH2\CH2—CH2
+ H20
CHZCHZCHZCHZCHZCDZH > HOCH2(CH2)4CD2H (4)

57

+
1,3-Propyl.~> CHZCHZCDZCHZCHZCHa (5)

leo
HOCHZCHZCD2CH2CH2CH3

+ +
CH3CH2CH2CH2CH2CD2 > CHZCHZCHZCDZCHZCHa (6)

, 1H20
HOCHZCHZCHZCDZCH2CH3

1,4-Et:~

 

+
1,5-Me:~> CHZCHZCHZCHZCDZCH3 (7)
lnzo

HOCHZCHZCHZCHZCDZCHa

Also the intervention of any symmetrical bridged ion (III)
or equilibrating substituted protonated cyclopropane
intermediates (IV), (IV') and (IV") cannot be significant

in the formation of l-hexanol.

CHZCHZCHs CHZCHZCH3 CHZCHZCH3 CHZCHZCH3
I I I I
[/ctz CT? ‘iiTH H1; fi/CH
[I + \\\ \\ // :///
/ _\_
C’H2_--__:'_:;_CD2 Hz—IDZ CH2 D2

 

(III) (Iv) (IV')

2. Secondary Alcohols

The formation of secondary alcohols can be reasonably
explained by successive 1,2-hydride shifts from the first
formed primary carbonium ion followed by the capture of
newly formed secondary carbonium ions by solvent. Thus,the

formation of two different 2-pentanols from the deamination

58
of 1-pentylamine-1,1-g2 can be rationalized by the reaction
sequence given below:

+ 112-H:~ + H20
CH3CH2CH2CH2CD2 -—-——-—->CH3CHZCHZCHCHD2

 

>CH3CH2 CH2 CHCHD2
OH
l 11 I 2-H:~ l
'1‘ H20
CH3CH2CHCH2CHD2

 

>CH3CH2CHCH2CHD2

OH

CH3CHCH2CH2CHD2

 

>CH3CHCH2CH2CHD2

OH
.2

The above sequence also explains, satisfactorily, the forma-
tion and the isotopic distribution of 3—pentanol lg,

From the deamination of 1-pentylamine-2,2-g2 and 1-
pentylamine-3,35g2 three different 2-pentanols are obtained.
These can be explained by reversible 1,2-hydride (deuteride)
shifts of secondary carbonium ions, as is illustrated in
the scheme on the following page. Since the 1,2-deuteride
shift to the secondary carbonium ion 12 would be slower than
the 1,2-hydride shift, the amount of alcohol g formed would
be smaller than that of alcohol 3, This is borne out by
the observed result. In addition, the 1,2-hydride shift
to the secondary carbonium ion does not compete successfully
with the capture of the latter by water—-since alcohol 1 is
formed in much smaller amounts than 3-pentanol l§° This
factor would be responsible for further decrease in the
rate of subsequent 1,2-hydride shifts leading to the forma—

tion of alcohols lg and ll. Consequently, the amounts of the

59
two alcohols formed would be too small to contribute

significantly to the mass-spectral data.

+ H20

 

,2D:~
CH3CH2CH2CD2CHzl—————7' CH2CH2CH2CDCH2D———> CH3CH2CH2CDCH2D
I
OH
+ gidifllzv *' 1 2- -H:~
CH2CH2CHDCHCH2D >CH2CH2CHCHDCH2 D<——————>CH2CHCH2CHDCH2D
.11
1H2o 1’2_H:~' lfH2o 1H2o
CH2CH2CHDCHCH2D CH2CH2CHCHDCH2D CH2CHCH2CHDCH2D
I I I
OH 0H 0H
5 .12 .1

+
CH2CH2CDCH2CH2D-eéaégé3 CH2CHCHDCH2CH2D

1H2o 1H2o
CH2CH2CDCH2CH2D CH2CHCHDCH2CH2D

I I

OH OH

19. 17

The available data do not allow any definite conclusions
to be drawn regarding the occurrence of 1,3-hydride (deu-
teride) shifts, followed by successive 1,2—hydride shifts.
However, it may not be unreasonable to assume that these
shifts do not occur in the present systems, since rearrange-
ment by such a mechanism has been found to be inoperative
in the formation of 2-butanols from the deamination of
labeled 1-butylamines (42).

The data for the secondary alcohols from the deamina—
tion of 1-hexylamine-1,1-d2 can also be readily accommodated

by successive 1,2-hydride shifts. The following scheme

60

represents the rearrangements occuring in the hexyl system.

 

+ 1,2-H:~ + H20
CH3CH2CH2CH2CH2CD2 _—_> CH3CH2CH2CH2CHCD2H ‘
”1'2_H:~ CH3 (CH2 )2cHCD2H
0H
+ H20
CH2CH2CH2CHCH2CD2H—> CH2CH2CH2cHCH2CD2H
111,2-H:~ OH
+ 1 2‘- -~ + H20
CH2CHCH2CH2CH2CD2H gig CH2CH2CHCH2CH2CD2H l
CH3CH2CHCH2CH2CD2H
OH

One evidence for the intermediacy of protonated cyclo-
propanes in the deamination of 1-propylamine is the forma-
tion of cyc10propane. No cyc10propane or its derivative
has been identified (40) in the products from the deamina-
tion of pentylamines. This observation, coupled with the
absence of scrambling of the carbon skeleton, makes it
possible to assume that no such intermediate intervenes in
the deamination of the pentyl system.

From the foregoing conclusions, it is possible, without
making any attempt to determine the nature of the dissoci-
ation step, to write the mechanism of the rearrangement

and formation of olefins, as given in the following sequence

61

CH3CH2CH2CH=CD2
_1_§
t-H
+ H20
CH3CH2 CH2CH2 CDzNHz "'"> CH3 CH2 CH2 CH2 CD2

 

> CH3CH2 CH2 CH2 CD2 OH

 

 

 

 

11 ,2-H:~
_H+ + H20
CH3CH2CH2CH=CD2‘“-- CH3CH2CH2CHCD2H > CH3CH2CH2CHCD2H
I9. 0H
+ " .
CH2CH2CH=CHCD2H ((1,2-H:~
212' _H+ + H20
CH3CH=CHCH2CD2H <———-CH2CH2CHCH2CD2H > CH3CH2CHCH2CD2H
2.1. 0H
+ lt132‘H3~
.22
-H+ + H2O
CH2=CHCH2CH2CD2H < CH3CHCH2CH2CD2H > CH3CHCH2CH2CD2H
I
22 on
+
21

The relative percentage compositions of 2-pentanol and
3-pentanol in Table XXIV are somewhat illustrative of the
mechanism of the formation of alochols. The amount of
Z-pentanol from 1-pentylamine-2,2-g2 is about 1% less than
that from 1-pentylamine-1,1—gb. This is probably due to
the fact that in the former case a deuteride shifts, where-
as in the latter a hydride shifts. For the same reason,
it can be seen, that the 3-pentanol from deamination of
1-pentylamine-3,3-g2 is formed in smaller amounts than those

from the other labeled 1-pentylamines.

SUMMARY

The following conclusions have been derived from the

results of deamination of 1-pentyl and l-hexyl amines.

1.

The alcohols are formed irreversibly from unrearranged
or rearranged carbonium ions or their precursors from
the starting amines.

No 1,5-, 1.6-hydride nor any alkyl shifts occur during
deamination. The normal alcohols have the same iso-
topic compositions as the starting amines.

No alkyl bridged symmetrical intermediates or equi-
librating protonated cyclopropanes intermediates inter-
vene to any extent in the rearrangement.

1,2vadride shifts are slower than the capture of car-

bonium ions by water.

62

EXPERIMENTAL

1. Preparation of Trimethylsilyl Ether Derivatives of

Pentyl and Hexyl Alcohols

Trimethyl silyl ethers of the alcohols were prepared
by adding a drop of trimethylchlorosilane (Stauffer) to
2:1 molar mixture of alcohol and hexamethyl disilazane
respectively, in a small flask, fitted with water cooled
reflux condenser attached to a drying tube filled with
"Drierite". The mixture was heated on a steam bath over-
night. The silyl ethers were collected by vapor phase
chromatography using a 20' x 1/4" 20% Carbowax 20M on

60/80 Chromosorb W column at 70-900, 30 psig He.

2. Preparation of l-Pentylammonium Perchlorate—1,17512

Lithium aluminum deuteride (0.12 mole) in 250 m1 of
ice—cooled anhydrous ether freshly distilled from lithium
aluminum hydride was placed in a 500 ml three-necked flask,
equipped with a water-cooled reflux condenser, a drying
tube filled with "Drierite", a "Teflon" bladed trusbore
stirrer and an addition funnel with equalizing arm. A
solution of 0.12 m (12g) of pure valeronitrile (K and K
Laboratories, B.P. 80-850 at «402 mm) in 30 ml of anhydrous
ether was added dropwise, at 0°, to the rapidly stirred
slurry of lithium aluminum deuteride in ether. After the

addition was completed, the mixture was refluxed for three

63

 

64
hours on a steam-bath and stirred at room temperature for
an additional three hours. The mixture was then hydrolyzed
at 00 by carefully adding 8 ml of water, 5 ml of 20% sodium
hydroxide solution and finally 10 ml of water. The super-
natant ether solution was decanted off, The white inor-
ganic solid was stirred three times with 15 ml portions of
ether. The ether extracts were mixed and dried over anhy-
drous magnesium sulfate.

The ethereal solution was then neutralized with 71%
perchloric acid. Ether and water were distilled off on a
rotary evaporator at 80°, leaving behind crystals of 1-
pentylammonium perchlorate-1,1-g2. The crystals were washed
with petroleum ether and dried in "vacuo". l-Pentylammonium
perchlorate-1,1-g2 (16.5 g) was thus obtained. (Yield is

72% based on the amount of valeronitrile used.)
3. Deamination of l—Pentylammonium Perchlorate—1,1fd2

A solution of 0.0465 mole (8.75 g) of l—pentylammonium
perchlorate-1,1-d2 in 0.0396 m perchloric acid (5.57 g of
71% HClO4) and 40 ml of water was made and extracted with
ether. The aqueous layer was placed in 100 ml three-necked
flask, equipped with addition funnel with equalizing arm,
‘water-cooled reflux condenser, a teflon coated magnetic
stirring rod and a thermometer. A solution of 0.093 m
(614 g) of sodium nitrite in 25 ml of water was added
slowly with constant stirring for an hour and a half. The

maximum temperature reached was 31°. The mixture was stirred

65
magnetically for five hours, when it was saturated with
sodium chloride and extracted three times with portions of
ether. The combined ether extracts were washed successively
two times with saturated sodium chloride solution and two
times with saturated sodium bicarbonate solution and dried
over anhydrous magnesium sulfate. Distillation of most of
the ether from the ethereal solution left behind 2.5 g of
the product mixture. The mixture of alcohols was separated
from the latter by preparative gas chromatography from a
nine foot 25% Carbowax column at 136° and 8 psig He, on a
Perkin-Elmer model 154 vapor refractometer.

The trimethylsilyl derivative of the alcohol-mixture
collected above was prepared. The ether from 1—pentanol
and the mixture of trimethyl silyl ethers of Z-pentanol
and 3-pentanol were collected and mass spectral analysis

carried out.

4. Preparation of l—Pentylammonium Perchlorate-2,25512

 

A. Preparation of Diethyl Propylmalonate.

Sodium (2.5 g-atoms) cut in small pieces was dissolved
in 1 liter absolute ethanol and 2.5 moles (380 ml) of malonic
ester added in a steady stream over a period of thirty min-
utes, followed by addition of 2.5 moles (400g) of propyl
bromide, keeping ethanol at steady reflux. The mixture was
then refluxed for an additional thirty minutes, at which
time the solution was neutral. The solid sodium bromide

from the product mixture was filtered off by suction and

66

dissolved in 800 ml of water and 15 ml of concentrated
sulfuric acid. The light brown filtrate was concentrated
on a rotary evaporator at 60° and mixed with the solution
of sodium bromide in water and sulfuric acid. The clear
ester solution was separated and aqueous layer extracted
with ether. The ether extracts and the ester were mixed,
dried over anhydrous magnesium sulfate and ether evaporated
off on a rotary evaporator.

Unreacted ester, from the ester product was removed
by shaking the ester solution exactly one minute with 50 ml
of 20% sodium hydroxide solution and washed with 100 ml of
10% hydrochloric acid. Yield of ester is 2.15 moles (86%)

(43,44).

B. Preparation of Pentanoic—2,2—d2 Acid.

 

Diethyl propylmalonate was hydrolyzed by adding the
ester from above preparation to a hot solution of 537 g
of potassium hydroxide in 430 ml of water in a three-necked,
2-liter flask, equipped with an outlet for removal of
ethanol. The mixture after heating on a steam bath for
8 1/2 hours, was acidified in the cold, by slow addition
of 650 ml of concentrated hydrochloric acid. The white
solid was extracted several times with ethanol. Removal
of the solvent left behind 170 g of propyl malonic acid.
The latter was exchanged six times with deuterium oxide,
by heating under reflux for overnight,a solution of the

diacid in 250 ml of deuterium oxide. The diacid was then

67
decarboxylated by heating it under reflux, in an oil bath,
at 140° for overnight. About 40 g of pentanoic acid-2,2-g2

was obtained (B.P. 186-7°).

C. Preparation of Pentanoic-2,2-g2 Acid Chloride.

 

Thionyl chloride (0.397 m) distilled successively from
quinoline (50 g of thionyl chloride + 10 ml quinoline) and
from linseed oil (50 g of thionyl chloride + 20 ml of linseed
oil) was added dropwise to 0.37 mole (39g) of pentanoic
acid-2,2-g2, placed in three-necked flask, equipped with
a water-cooled condenser, fitted with a drying tube con-
taining "Drierite". stirrer and an addition funnel with
equalizing arm. The mixture after two hour reflux, was
cooled and excess thionyl chloride distilled off. Weight

of undistilled ac1d chloride is 36 g (81%).

D. Preparation of Valeronitrile-2,24d2

 

In a l—liter, three-necked flask equipped with a
condenser, a "Teflon" bladed Tru-bore stirrer and addition
funnel, cooled by a freezing mixture, are placed 250 ml of
ammonium hydroxide solution. The acid chloride (0.3 mole)
is added slowly, so as to keep the temperature of the mix-
ture below 15° and the mixture stirred for two hours after
completion of the addition. The solvent is then rotoevapor-
ated off at 75°, the concentrated solution extracted several
times with ethyl acetate, and pentanoic—2,2-d2 acid amide
crystallized out from the ethyl acetate solution. The

aqueous solution from the above extraction, on concentration

68
also gave more amide. Yield is 65% from acid chloride,
M.p. 100°.

Dehydration of the amide to valeronitrile-2,2-d2 was
carried out by heating for four hours, under reflux, the
mixture of 0.195 m (20.1g) of the amide and 0.3 m (39.29)
of purified thionyl chloride. The unreacted thionyl
chloride was very carefully decomposed, in the cold, by
dropwise addition of cold water, until no more hydrochloric
acid and sulfur dioxide fumes evolved. The mixture, after
making alkaline, with sodium hydroxide solution, was ex—
tracted with ether. The ethereal solution, after washing
with saturated sodium chloride and water was dried over
anhydrous magnesium sulfate. Distillation under reduced
pressure gave 11 g of pure valeronitrile—2,2-d2 (66% from

amide).

B. Preparation of 1-Pentylamine-2,2—g2.

 

Valeronitrile-2,2-d2 (0.129 mole) in 30 ml of dry ether
was added slowly, in the cold, to 0.129 mole (4.9 g) of
lithium aluminum hydride (Metal Hydrides) in 250 ml of
anhydrous ether. The mixture, after three hours reflux on
a steam bath was stirred at room temperature for another
three hours and hydrolyzed with sodium hydroxide solution.
The ethereal solution was decanted off, mixed with the ether
extracts.obtained from extraction of the white inorganic
solid residue with ether, and dried over anhydrous magnesium

sulfate.

69
The ethereal solution was then neutralized with 71%
perchloric acid and evaporation of the solvent on a rotary
evaporator gave a slurry of crystals, which was dried under
vaccuum, giving 14.5 g of 1-pentylammonium perchlorate-

2,25g2 (Yield 60% from nitrile).

5. Preparation of l-Pentylammonium Perchlorate-3,3fid2

 

A. Preparation of Butyric—2,2—g2 Acidjd.

 

Ethyl malonic-2hd-acid-g2 (supplied by Ramon Mount)
was decarboxylated by heating it under reflux, in an oil-
bath for overnight at 150°. The acid was distilled under
reduced pressure and the fraction boiling between 75-80°
at 30 mm was collected. (V.p.c. using 6' x 1/4" Apiezon
at 118° and 30 psig He, showed the acid to be pure). The

nmr showed no B—methylene protons.

B. Preparation of 1-Butanol—2,27g2.

 

An ethereal solution of 0.966 mole (87 g) of butyric-
2,2-92 acid-g was added to a slurry of 1.2 mole (45.6 g)
of lithium aluminum hydride in 250 ml of anhydrous ether.
The mixture, after three hours reflux and one hour of stir—
ring at room temperature was hydrolyzed with water and
sodium hydroxide solution. The ethereal solution was then
dried over anhydrous magnesium sulfate and distilled to

give 40.6 gm of 1-butanol-2,2-92.

70

C. Preparation of 1-Bromobutane-2,24g2.

To 40.6 g of 1-butanol-2,2—§2 in a 300 ml three-necked
flask, equipped with an addition funnel, a water cooled con-
denser fitted with a drying tube containing ”Drierite" and
a small teflon coated magnetic stirring rod, was added
0.178 mole (48.239) of phosphorous tribromide at such a
rate, so as not to raise the temperature above 0°. The
mixture, after overnight stirring was refluxed on a steam
bath for two hours. It was then shaken with 80 ml of water,
the organic layer was separated, washed three times with
saturated sodium bicarbonate solution and two times with
water, dried over anhydrous magnesium sulfate, and distil-
led. The fraction boiling between 97-101° was collected

(yield 61%).

D. Preparation of Valeronitrile—3,3-d2.

 

A solution of 0.33 mole (16.17 g) of sodium cyanide in
21 ml of water was made by heating the mixture on a warm
water bath under gentle reflux. The solution of 0.302 mole
(42.7 g) of 1-bromobutane-2,2-d2 in 48 ml of methanol was
added and the reaction mixture was refluxed for 28-30 hours.
Sodium bromide was filtered off through a sintered glass
funnel at the pump, washed with methanol and ether. The
washings and the filtrate were mixed and the methanol was
distilled off. The remaining solution was diluted with
water and distilled further until no more oily drops were

collected. The aqeuous layer separated from nitrile was

71
extracted with ether, the ether extract combined with nitrile
and shaken with 50% hydrochloric acid to remove any methanol
and isonitrile, and finally washed with saturated sodium
carbonate and water successively. The solution after dry—
ing over anhydrous magnesium sulfate was distilled under

reduced pressure to give 15.7 gm of pure nitrile (60%)

E. Preparation of 1-Pentylamine-3,3—g2.

 

To slurry of 0.153 mole (5.8 g) in 250 ml of anhydrous
ether, was added a solution of 0.153 mole (13 g) of valero-
nitrile-3,3-g2 and the mixture after refluxing for three
hours on a steam bath and stirring for another three hours
at room temperature, was hydrolyzed with water and sodium
hydroxide solution. The ethereal solution after drying
over anhydrous magnesium sulfate was neutralized with 71%
perchloric acid, the solvent was removed on a rotary evapor—
ator, the crystals washed with petroleum ether and dried
in "vacuo". 1-Pentylammonium perchlorate-8,3-d2 (20 g)

was thus obtained (70% from nitrile).

6. Deamination of l-Pentylammonium Perchlorate—2,2-g2 and

 

1-Pentylammonium Perchlorate-3,3-g2

 

A solution of 0.05 mole (9.5 g) of deuterated 1—pentyl-
ammonium perchlorate in 25 ml of distilled water and 0.0427
mole of perchloric acid (5.9 g) of 71% perchloric acid was
extracted with ether and the aqueous layer heated on a steam

bath to remove traces of ether. A solution of 0.1 mole

72
(6.9 g) sodium nitrite in 25 ml of water was added over a
period of one hour, the mixture stirred for five hours,
salted out with sodium chloride and extracted with ether.
The ether extract after washing with saturated sodium chlor-
ide and sodium bicarbonate solution was dried over anhy-
drous magnesium sulfate and distilled, leaving 2.5 g of the
product mixture. 1-Pentanol and the mixture of 2-pentanol
and 3—pentanol were collected by preparative gas chromato-
graphy using Carbowax column at 90°, 50 psig N2 on H.M.
Scientific 776 Prepmaster Jr. The trimethylsilyl ether
derivatives of the 1-pentanol and the mixture of 2—pentanol
and 3-pentanol were prepared and collected by vapor phase

chromatography.
7. Preparation of Authentic Deuterated Alcohols

A. Preparation of 1—Pentanol-1,1-§2.

 

A solution of 0.01 mole (1.01 g) of valeric acid in
10 ml of anhydrous ether was added to a slurry of 0.01 mole
(0.42 g) of lithium aluminum deuteride in 50 ml of anhy—
drous ether. The reaction mixture after reflux on a steam
bath for four hours was hydrolyzed and ethereal solution
after drying over anhydrous magnesium sulfate was distilled

to give 0.6 g of l-pentanolal,ljd2.

B. Preparation of 1-Pentanol-2,2-d2.

 

 

To a slurry of 0.01 mole (0.42 g) lithium aluminum

hydride in 50 ml of anhydrous ether, was added a solution

73
of 0.057 mole (0.6 g) of valeric acid-2,2fid2 in 10 ml of
anhydrous ether. The mixture was stirred for one hour and
refluxed on the steam bath for three hours and hydrolyzed
with sodium hydroxide solution. The ethereal solution after

distilling gave 0.4 g of 1-pentanol-2,2—d2.

C. Preparation of l—Pentanol-3,3-d2.

‘t-

 

Preparation of Valeric Acid—3,3-d2. Magnesium turnings

 

(0.025 g-atom) was placed in 25 ml of dry ether in a 100 ml
three-necked flask, equipped with a condenser fitted with
drying tube and addition funnel.

A crystal of iodine and 2 ml of the solution of 1-bromo-
butane-2,2-g2 in 10 ml of dry ether were added to the mag-
nesium in ether and the reaction mixture refluxed on a steam
bath until vigorous reaction took place. Remaining ethereal
solution of 1-bromobutane—2,2—g2 was added, the mixture
stirred for one hour at room temperature and poured quickly
over 6 g of dry ice. The thick paste obtained after a
vigorous stirring, was decomposed with 10% hydrochloric acid
to get a clear two-layered solution. The upper layer con—
taining valeric acid-3,3-d2 was separated and converted into
sodium salt. The aqueous solution containing the sodium
salt was separated from the ether layer containing impuri-
ties, acidified with 10% hydrochloric acid and extracted
with ether. The ether layer after drying over anhydrous
magnesium sulfate was distilled to give 1.3 g of valeric

74

Preparation of 1—Pentanol-3,35g2. A solution of 1.2 g

 

 

(0.011 mole) of valeric acid-3,3-g2 in 10 ml of dry ether
was added, in the cold, to a slurry of 0.013 mole (0.5 g)

of lithium aluminum hydride in 50 ml of dry ether. The
mixture was refluxed on a steam bath for one hour, stirred
at room temperature for one hour, and hydrolyzed with sodium
hydroxide solution. The ethereal solution after drying over
anhydrous magnesium sulfate, was distilled to give 0.5 g

of 1-pentanol-3,3-d2.

D. Preparation of 2-Pentanol-25d_and 3-Pentanol-35Q,

 

A solution of 0.01 mole (0.86 g) of the respective
ketone in 20 ml of dry ether was added to 0.01 mole (0.42 g)
of lithium aluminum deuteride in 50 ml of anhydrous ether.
The mixture was refluxed for 3 hours on a steam bath, after

which it was hydrolyzed by adding 1 ml of water, 3 ml of
20% sodium hydroxide solution and 3 ml of water. The clean
ether solution was decanted off, dried over anhydrous mag-
nesium sulfate and distilled giving 0.67 g of deuterated

alcohol.

8. Preparation of l-Hexylammonium Perchlorate-1,15d2.

 

An ethereal solution containing 0.12 mole (11.64 g)
of amylnitrile was added, in the cold, to a suspension of
0.12 mole (5 g) of lithium aluminum deuteride in 250 ml of
anhydrous ether. The ethereal solution containing 1-hexyl-
amine—1,1—d2 after the work up of the product mixture was

neutralized with 71% perchloric acid. Removal of the solvent

75
on a rotary evaporator gave crystals of l-hexylammonium
perchlorate-1,1-d2. The latter were washed with petroleum

ether and dried under vaccuum (yield 70% from nitrile).

9. Deamination of 1-Hexylammonium Perchlorate—1,11QB.

 

A solution of 0.04 mole (8.2 g) of l—hexylammonium
perchlorate-1,1-g2 in 25 ml of water and 0.033 mole (4.64 g)
of 71%) perchloric acid was deaminated by adding to it a
solution of 0.08 mole (5.52 g) of sodium nitrite in 25 ml.

The reaction mixture after stirring for five hours
was salted out with sodium chloride and extracted with
ether. The ether extract was washed, successively, with
saturated sodium chloride and sodium bicarbonate solution
and after drying over anhydrous magnesium sulfate was
distilled giving 3.0 g of the product mixture. 1-Hexanol
and the mixture of 2—hexanol and 3-hexanol were collected
by preparative gas chromatography from 6' x 1/4" 20%

Carbowax 20M on 60/80 Chromosorb W at 105° and 30 psig He.

10. Preparation of Authentic 1-Hexanol-1,14g2.

 

A. Preparation of Hexanoic Acid.

 

A mixture of 0.06 mole (5.82 g) of amylnitrile, 0.115
mole (4.6 g) of sodium hydroxide and 20 ml of water was
placed in 100 ml round—bottom flask with a water—cooled
reflux condenser and refluxed on a heating mantle until
nitrile layer disappeared. The product mixture was then

acidified with 50% sulfuric acid, the upper acid layer

76
separated. The aqueous solution was then extracted with
ether, the ether extract and the acid layer were combined,
dried over anhydrous magnesium sulfate and distilled.

Obtained was 5.5 g of the pure acid (80% yield).

B. Preparation of 1-Hexanol—l,14d2.

 

The reduction of hexanoic acid was accomplished by add-
ing a solution of 0.01 mole (0.42 g) of lithium aluminum
deuteride in 50 m1 of anhydrous ether. The mixture, after
three hour reflux and hydrolysis with sodium hydroxide,
gave an ethereal solution, which was dried over anhydrous
magnesium sulfate and distilled. 1-Hexanol—1,1-_d2

(0.75 g) was thus obtained (75% yield).

10.

11.

12.

13.

14.

15.

16.

17.

BIBLIOGRAPHY

Whitmore, F. C., J. Am. Chem. Soc., 22“ 3274 (1932).

Whitmore, F. C., and D. P. Langlois, ibid., 54, 3441
(1932).

Meerwein, H. and K. V. Emster, Chem. Ber., 52“ 2500
(1922).

 

Roberts, J. D., C. C. Lee and W. H. Sannders, Jr.,
J. Am. Chem. Soc., 22x 4501 (1954).

 

Berson, J. A., in "Molecular Rearrangements", Part I
P. pemayo, Ed., Interscience Publishers, Inc., New
York, N. y. 1963, PP 139-155.

Roberts, 34 D. and M. Halmann. J. Am. Chem. Soc., 15,
5759 (1953).

 

Roberts, J. D. and J. A. Yancey, ibid, 24, 5943 (1952).

Reutov, O. A. and T. N. Shatkina, Doke, Akad, Nauk SSSR,
133, 606 (1960)(p. 851, Eng.).

Reutov, O. A. and T. N. Shatkina, Izv. Akad. Nauk SSSR,
Otd Khim, Nauk, 2038 (1961) (p. 1900, Eng.).

 

Reutov, O. A. and T. N. Shatkina, Tetrahedron,.1§/ 237
(1961). 7

Karabatsos, G. J. and C. E. Orzech,Jr.” J. Am. Chem.

Soc., (234’, 2838 (1962).

Lee, C. C., J. E. Kruger, and E. W. C. Wong, ibid.,
§Z, 3985 (1965).

Lee, C. C. and J. E. Kruger, ibid., §ZJ 3986 (1965).

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