THE SYNTHESIS OF I:.33.Za-CHOLESTA-4-ENE-TRIOL By Yue-Yeh Lin Chang A THESIS Submitted to Michigan State University in partial fulfiiiment of the requirements for the degree of MASTER OF SCIENCE Department of Chemistry 1978 ABSTRACT THE SYNTHESIS OF Io,3o,7o-CHOLESTA-4-ENE-TRIOL By Yue-Yeh Lin Chang An approach to the synthesis of cholesta-S-ene-l,7—dione (1) has been devised and successfully implemented to the key inter- mediate lu,3o,7a-cholesta-4-ene-triol (g). Thus reduction of either la,2a,6a,7a-diepoxy-cholesta-4-ene-3-one (a) or 3a-acetoxy- lo,2o,6a,7a-diepoxy-cholesta-4-ene (Q) with lithium aluminum hydride gave g. Compound 3 was prepared from cholesterol in threee steps either by peracid epoxidation or autoxidation of la,2a-epoxy- cholesta-4,6-diene-3-one. Although the desired functionality and stereochemistry was achieved. the yields were low. To get around this difficulty, the deactivating carbonyl group was removed by reduc- tion with sodium borohydride. and the resulting hydroxyl function protected by acetylation. Through this modification. compound 5 was readily propared in good yield by epoxidation with m-chloroperbenzoic acid. The stereOchemical assignments made here were confirmed by high resolution pmr spectrometry. DEDICATION To My Parents ACKNOWLEDGMENTS I would like to express my sincere appreciation to my advisor, Professor William H. Reusch, for his patient guidance, assistance and encouragement throughout my research. I would also like to thank Professors E. LeGoff, A. Timnick and M. Rogers for serving on my committee. Appreciation is also extended to my colleagues for stimulating and informative discussions and their friendship. I also want to express my appreciation to my sister, Yue-Mei Lin whose love and understanding over the years have made this opportunity possible. Finally, I wish to express my deepest appreciation to my husband, Biau-Hung, for his love. inspiration and understanding. TABLE OF CONTENTS Page INTRODUCTION . . . . . . . . . . . . . ........... l RESULTS AND DISCUSSION . . . . . .............. 7 EXPERIMENTAL . . . . . . ..... . . . .......... 22 General . . . . . . . . . . . . . . . . . ....... 22 Cholesta-l,4,6-triene-3-one lg. ........... . 23 la,2a-Epoxy-cholesta-4.6-diene-3-one lg ........ 23 la,2a,6a,7a-Diepoxy-cholesta-4-ene-3-one 1Q . . . . . . 24 la.3a.7a-Cholesta-4-ene-triol ll. . . . . ....... 25 la,2a-Epoxy-3a-hydroxy-cholesta-4,6-diene lg. . . . . . 27 3a-Acetoxy-la,Za-epoxy-cholesta-4,6-diene la ...... 27 3a-Acetoxy-la.2a.6a,7a-diepoxy-cholesta-4-ene 2Q. . . . 28 REFERENCES 0 O O O O O O O O O O O O O O O O O O I O O O O o 29 APPENDIX 0 O O O O O O O O O O O O O O O O O O O O O O O O O 3] Figure d O NO CD \I m 01 uh (A) N o d d d d d —J H d \l 0'. 0" h w N -" o o o o o o o o 0 LIST OF FIGURES The Synthesis of lg . . . Pmr Spectra of lg . . . . . . . Pmr Spectra of ll . . . . Pmr Spectra of lg . . . . . . . . . . . ..... Pmr Spectra of gg . . . . Double Resonance Pmr Spectra of lg ........ Infrared Spectrum of lg . . . . . Infrared Spectrum of ll . Infrared Spectrum of lg . . . Infrared Spectrum of lg . Infrared Spectrum of lg . Pmr Spectrum of lg. . . . Mass Spectrum of lg . . . Mass Spectrum of lg . . . Mass Spectrum of ll . . . Mass Spectrum of l2 . . . Mass Spectrum of £2 . . . INTRODUCTION Reductions of unsaturated carbonyl compounds by alkali metals in ammonia solutions generates reactive nucleophilic intermediates which are capable of intra- and inter-molecular attack on electro- 1'3 This course of reaction was first observed 1.9’2_ philec functions. during lithium in ammonia reduction of 10-hydroxymethyl-A octalone tosylate ley Stork and co-workers.2 Tsc> H 09. 2 M. . v» d It is now recognized that cycloprOpane ring formation during dissolving metal reductions of bi- and polyfunctional compounds is probably a general phenomenon. In fact, even relatively reactive 3 have been prepared by this kind compounds such as cyclopropanols of transformation. Thus reduction of 2,2.4.4,6,6-hexamethyl cyclohexane-I,3,5-trione.3lwith lithium in liquid ammonia produced the corresponding cyclopropanediolllc4 o H -—-+> o 0 on 3 4 M M In an extension of this transformation to vinylogs of 1,3-diketones, Nieland-Miescher ketone.§lwas found to give the versatile cyclopropanol‘gf during lithium and ammonia reduction. up» 33:10 ‘Vh Eight alkyl-substituted derivatives of Nieland-Miescher ketone 5 were prepared and subjected to lithium in ammonia reduction with similar results.6 The steroids 9.11o- and B-oxido-17-methyl testo- sterones lg and lg did not yield the expected products gg and‘gg upon lithium in ammonia reduction, but gave only the saturated compounds 9a and 9b.7 M V» 3 However. methyl 3.12-diketoqA4’9(11)-choladienate.LQdid produce 8 the expected cyclopropane 11. M CH 08 2 .19 as To extend the cyclopropanol findings.to steroids, a prepara- tion of steroid lg (cholestane series) was needed. Reduction of u with lithium in amnonia should yield cyclopropane lg. Since no steroid having the functionality shown in formula lg has been reported in the literature, a major part of this thesis is devoted to work leading to the synthesis of steroid lg. Cholesterol is an enexpensive and promising starting material for the synthesis of homoconjugated enedione lg. lo,23-Epoxy- cholesta-4,6-dien-3-one lg was synthesized by E. Glotter9 et al by DDQ (2,3-dicyano-5.6-dichlorobenzoquinone) dehydrogenation of cholesterol, followed by alkaline epoxydation (Equation 1). To provide the required 7-carbonyl function. epoxydation at positions 6 and 7 has been examined and is described in this thesis. (1) Preparation of 7,5-epoxyenones from conjugated dienones can be carried out by a number of methods. the most frequently employed and generally applicable of which is peracid oxidation.10 The most common peracids used to convert dienones to epoxides are perbenzoic acid.ll monoperphthalic acid12 and m-chloroperbenzoic acid.13 The latter is convenient to use. since it is commercially available and reacts at a somewhat faster rate than perbenzoic acid. Peracid epoxidation reactions proceed by an electrophilic attack upon the double bond. thus the rate of epoxidation is very sensitive to the electron density at the olefinic site.10 The preferential epoxidation of the v.6-double bond over the c.8-double bond in conjugated dienones reflects this characteristic. In addition to peracid epoxidation. other less general methods 14 15 are available. Among these is the autoxidation of olefins. This autoxidation process is not well understood but probably involves a free radical mechanism of the following type:16 \ R—O—O- + / =C —-—c. R-O-O-C'I-C- I R—O-O—SZ—c. ——o \C— / .., RO° \ o’ / R0° "’ RH ———o- ROH + R. In 1974, H. Hart et al described a synthetically useful 17 Conjugated dienones and epoxidation with molecular oxygen. diene esters are epoxidized at the v.5-double bond by molecular oxygen when heated in solvents which have readily abstractable hydrogen atoms. The following mechanism was suggested: R- + 02 —. R02- 0 + N—s RO-O-C-C'J-‘CL-"Cz'cxo ——'* RO' + c—lc—czc-czo RO°‘RH -——-.ROH+R. Because of competition among other free radical processes. the yields were not high. However. the v.6-epoxidation of conjugated dienone by this simple approach is still of preparative value. It is the purpose of this thesis to examine some of these epoxidation reactions of conjugated dienones and employ a number of modifications to overcome some difficulties encountered with selectivities and yields. RESULTS AND DISCUSSION 1a.2a,6a.7a-Diepoxy-cholesta-4-ene-3-one was prepared from cholesterol by the sequence of steps outlined in Figure 1. Cholesterol was oxidized with 2,3-dicyano-S,6-dichloro-benzoquinone 18’19’20 which was epoxi- (DDQ) to cholesta-I.4,6-triene-3-one lg. dized by alkaline hydrogen peroxide as described by E. Glotter et al9 to give crystalline lo,2a—epoxy-cholesta-4,6-diene-3-one I5. Its melting point; the infrared and nuclear magnetic resonance (NMR) spectra all agreed well with the literature values. Treatment of epoxyketone lg with excess m-chloroperbenzoic acid for twelve hours afforded 1a,2a.6a,7a-diepoxy-cholesta-4-ene-3-one lg, accompanied by more-polar by-products from which the diepoxy- ketone lg was separated in 30% yield by crystallization and column chromatography. Figure l. The Synthesis of lg Compound lg has not been previously described. Its structure is established by its spectral properties and chemical transforma- tion. The molecular formula C27H4OO3 was comfirmed by the mass spectrum (parent peak m/e 412) and elemental analysis. The ir spectrum showed a strong absorption at 1675 cm"1 for a conjugated C=O, and the uv spectrum was also consistent with such conjugation, having a Amax at 250 nm. An examination of the proton nmr spectrum of 16 shows the presence of a double bond in the o,B-position, and epoxide rings in the o'.B' and y,6-positions. Although the T-60 spectrum does not show a clear splitting pattern for the four epoxy protons at positions 1, 2. 6 and 7 (Figure 2a), the 180 MHz nmr resolves them well (Figure 2b). Integration of this spectrum indicates the relative areas under the peaks at 63.53. 3.47 and 3.33 to be 1:2:1, suggesting the signals of Cz-H and C5-H have overlapped. Expansion of this region displays the splittings very well (Figure 2c). The proton at position 2 couples with Cl-H (doublet at 63.53) to form a doublet (J84 Hz) which is further split by a long range coupling with C4-H (J82 Hz) to form a doublet of doublets at 63.45. These doublets overlaps with a doublet from CG-H, which is coupled with C7-H (J-4 Hz). Finally C7-H gives a doublet at 63.33 which is further split by a small coupling with C8-H (J81 Hz).' (a) l A a l . A : - i .4 a 4.14 . 4 4 J ..... u u- an a. {p (b) ’ (.IZ 3.53 347 333 (C) 3.53 345 3.33 Figure 2. Pmr Spectra of lg 10 Assignment of stereochemistry to lg is based on the chemical transformation of lg into la.30,7a-cholesta-4-ene-triol ll with lithium aluminum hydride reduction (Equation 2). According to the Furst-Plattner rule21 , an oxirane ring fused to a rigid cyclohexane moiety usually undergoes ring-opening so as to form the trans-diaxial product. Consequently, ring-opening reduction of lg with lithium aluminum hydride should selectively form the la and 7a hydroxyl groups. Treatment of diepoxyketone lg with a large excess of lithium aluminum hydride in dry THF yielded la,3a.7a-cholesta-4-ene-triol, thus the a-configuration of the 6,7-epoxide ring of lg was confirmed. Had the 6,7-epoxide possessed the a-configuration. its reduction with lithium aluminum hydride should have furnished, by diaxial opening, the 68-hydroxy-isomer. ll The previously unknown triol ll was obtained as colorless crystals. Its structure was established by its mass, ir and nmr spectra and elemental analysis. The T-60 and l80 MHz spectra (Figure 3a and 3b) all showed an olefinic proton signal at 65.65 which is apparently due to the C4-H. Although the T-60 spectrum only showed two signals at 63.8-4.2, the l80 MHz nmr resolved them well into three signals which are due to the protons attached to hydroxyl bearing carbon atoms (C-l, C-3 and C-7). Integration indicates the relative areas under the peaks at 64.l5. 3.89 and 3.77 is l:l:l. as required by the assigned structure of triol ll. Because of its allylic location, the C3-H is found downfield from the other two carbinol protons at positions l and 7. Since the latter have similar chemical environments, they also have similar chemical shifts. Had the trial held a 6e-hydroxyl group instead of the 7a function. the proton at C-6, which is also allylic would have been close in chemical shift to C3-H. Furthermore. all the carbinol protons appear to have an equatorial orientation, as indicated by the relatively narrow and poorly defined splitting displayed by each. The two angular methyl resonance signals for C-l8 and C-lQ also help to establish the assigned structure of the triol. 12 (a) (b) I 4W” (’mew H" "M. ”A?“ Mi IV} H rm. 5'“ 4.15” 3.97 3-77 Figure 3. Pmr Spectra of ll 13 22 have tabulated the effect of functional Bhacca and Williams substitution at various positions on the chemical shifts of the C-l8 and C-19 protons for the So. l4o-androstane series. From the appropriate functional group increments, the calculated chemical shifts of the C-18 and C-19 protons in the isomeric 6B-bydroxy or 7a-hydroxy derivatives were compared with the observed values (Table l). The good correlation of the observed and calculated chemical shift differences (A) for the 7a-hydroxy derivative confirmed the assigned structure of the triol. In this comparison it is assumed that a 6a.7a-epoxide will open to the 76-hydroxy group, and a 65,73-epoxide will give a 63-hydroxy group (Furst- Plattner Rule). Table l. The Observed and Calculated Chemical Shifts of C-18 and C-l9 protons of ll W 5c-l8 5C-l9 A(6C_19 -6c_18) steroid increments methyl methyl used obs 0.670 0.953 0.293 calcd] 0.717 1.034 0.317 1a-0H, 3a-0H, 73-0H, 4 calcd2 0.751 1.234 0.483 la-OH, 3o-OH, 68-0H, 4 14 An effort was made to prepare compound lg by autoxidation of lg. When epoxyketone lg was heated in xylent at l20-l30o for 21 hr in the presence of air. diepoxide lg was formed in 21% yield with many side products. The mp; nmr and ir Spectra of this product were identical to the diepoxide obtained from the peracid reaction. Although the diepoxyketone lg could be synthesized either by peracid reaction or by autoxidation, the yields were all poor from a synthesis viewpoint. Attempts to improve the yield of diepoxide by using more peracid or a longer reaction time led to the appearance of polar by-products. The poor yield may be due to the electron-withdrawing effect of the conjugated carbonyl function in lg. To eliminate this inhibiting effect. epoxyketone lg was reduced by sodium borohydride to give the corresponding 3u-hydroxy-derivative lg. followed by acetylation with acetic anhydride in pyridine to give 3a-acetoxy-la.Za-epoxy-cholesta- 4,6-diene lg as colorless crystals in 90% yield (Equation 3). 15 Compound lg was identified by its mass, ir and nmr spectra and elemental analysis. Although the T-60 nmr spectrum of lg in CDCl3 does not show a clear splitting pattern at 65.5-5.9 (Figure 4a), integration of this spectrum indicates the area under this multiplet to be three protons, suggesting that the olefinic protons at positions 6 and 7 have overlapped with the C3-H. This was confirmed by the 180 MHz nmr (Figure 4b). Expansion of this spectrum (Figure 4c) gives good resolution of these signals. It clearly indicates that the broad singlet at 65.73 is from the proton at C-3 and the doublet at 65.58 (J8 10 Hz) is from the proton at C-6, coupled to the C7-H. which itself is a doublet of doublets at 65.9 due to a small coupling with the C8-H (J-2 Hz). The singlet at 65.0 is assigned to the other olefinic proton at C-4. Unexpectedly, the signal at 63.45 appears as a quintet. It is assigned to the Cz-H, which is coupled with C1-H to form a doublet (J84 Hz), and then further split by interactions with protons at C-3 and C-4. Since the long range coupling constant between Cz-H and C4-H is about the same magnitude as the coupling constant between Cz-H and 03-H, the doublet is split into a pair of overlapping triplets. (a) 01 A . ' A ‘ l A . A A . +g] l 4 A A I A A A . 1 A A l I A A A l A J 4‘ A I J 4 A J I J A A A I. 2’ . DJ CD 5’ "a 020 a. I) o (b) (e) .57 .573 .552 Figure 4. Pmr Spectra of lg 17 Peracid epoxidation of lg was then examined. In contrast to the reaction of diepoxyketone lg, compound lg was epoxidized quite readily by only a stoichiometric amount of m-chloroperbenzoic acid (m-CPBA) to yield Bu-acetoxy-la,26.6a,7a-diepoxycholesta-4-ene gg as colorless crystals (60-65% yield), accompanied by a small amount of more-polar by-products (Equation 4). Compound gg has not been previously described. Its structure is established by its soectral properties and chemical transforma- tion. The molecular formula C29H4404 was confirmed by the mass Spectrum (parent peak m/e 456) and elemental analysis, and the ir and nmr spectra were consistent with the assigned structure. Although the signal at 65.51 in the T-60 nmr lookd like a broad singlet (Figure 5a), integration of this spectrum indicates the relative area under this peak to be two protons, suggesting an overlap of signals from protons at position 3 and 4. These two (a) .— .— —— (b) 551547 343 51—78 3-/3 Figure 5. Pmr Spectra of gg 19 signals are well resolved by 180 MHz nmr into a pair of triplets at 65.54 and 5.49 (Figure 5b). The multiplet at 63.1-3.3 is also resolved into a quintet at 63.43 and two doublets at 63.28 and 3.13. An examination of a Dreiding molecular model of gg help to explain why the protons on C-3 and C-4 appear as similar triplets. As noted above. the long range coupling between CZ-H and C4-H is about the same magnitude as the coupling between Cz-H and C3-H. The formation of these two triplets indicates that the coupling constant between C3-H and C4-H also happen to be the same magnitude as the coupling constant between C2-H and C3-H. In order to have these coupling constants of the same magnitude, the orientation of the 3-0Ac and the 6,7-epoxy ring must both be alpha. On this basis. the configuration of compoind gg was established as Ba-acetoxy- la,2a.6¢,7a-diepoxy-cholesta-4-ene: 20 This rationalization was confirmed by a double-resonance experiment. Irradiation at the frequency of Cz-H induced the collapse of the C3-H and C4-H signals to two doublets (J=2 Hz, due to the coupling with each other), as shown in Figure 6a. Conversely. irradiation of either C3-H or C4-H resulted in the collapse of the C2-H quintet to a doublet (J=4 Hz, due to the coupling with Cl-H), as shown in Figure 6b. Treatment of gg with a large excess of lithium aluminum hydride in dry THF yielded the same triol ll obtained from lithium aluminum hydride reduction of lg (Equation 5). The mass, ir and nmr spectra and mp were identical. This chemical transformation further proves, by the diaxial opening rule, the the 6,7-epoxy ring of gg has the a-configuration; and indicates that the orientation of the 3-0H in triol ll is also alpha. (a) (b) ” Kilt} EXPERIMENTAL General Except as indicated, all reactions were conducted under dry nitrogen or argon, using solvents purified by distillation from suitable drying agents. Magnetic stirring devices were used for most small scale reactions and mechanical stirrers for large scale reactions. Organic extracts were generally dried over anhydrous magnesium sulfate. before being concentrated. The progress of most reactions was followed by thin layer chromatography (TLC), visualized by spraying with 30% sulfuric acid followed by heating or by ultraviolet (UV) light. Preparative TLC was carried out on 2 mm silica gel F-254 adsorbent on 20x20 cm glass plates. Visualization of preparative TLC was effected by UV light. Melting points were determined on a Reichert hot-stage microscope and are uncorrected. Infrared (IR) spectra were recorded on a Perkin-Elmer 237B grating spectrophotometer. Proton magnetic resonance (PMR) spectra were taken in deuterochloroform (CDCl3) solution with a Varian T-60 or Bruker Spectrospic (l80 MHz) spectrometers and are calibrated in parts per million (6) downfield from tetramethylsilane (TMS) as an internal standard. Ultraviolet spectra were recorded on a Unicam SP-800 spectrophotometer. Mass spectra (M5) were obtained 22 23 with a Hitachi RMU 6 mass spectrometer. Micro-analyses were performed by either Spang Microanalytical Labs. Eagle Harbor, Michigan or Galbraith Labs. Inc., Knoxville, Tennessee. Cholesta-l,4,6-triene-3-one (lg) To a solution of 5 g (0.013 mole) of cholesterol in lDO ml anhydrous dioxane (50 mg of steroid/ml) was added 9.75 g of 000 (0.042 mole). This mixture was refluxed for 25 hr. After filtration of precipitated hydroquinone*, the filtrate was diluted with methylene dichloride and passed through a short column of loo 9 neutral alumina (20 mg of alumina/mg of steroid), eluting with 500 ml CHZCl2 followed by 250 ml of 30% acetone in CHZClZ. Evaporation of the combined eluant gave 2.6 g of a pale yellow oily compound. Recrystalization from methanol or petroleum ether gave 2.2 g (44% yield) colorless crystals of lg, mp 85-860 (lit. 82-830). *The recovered 2,3-dicyano-5,6-dichlorohydroquinone was oxidized by nitric acid to 000. A slurry of 2,3-dicyano-5,6- dichlorohydroquinone (4.6 g, 0.02 mole) in water (20 ml) and concentrated hydrochloric acid (20 ml) was treated over l5 min. with concentrated nitric acid (6.2 g, 70.9%) at a temperature of 35:30. After all the nitric acid had been added, the yellow suspen- sion was stirred for 1/2 hr, filtered, washed with CCl4. and dried, yielding 4 g (87%) of 000. mp 212-213°. 24 la,23-Epoxy-cholesta-4,6-dien-3-one (lg) A solution of.le (1.0 9, 0.0026 mole) in methanol (35 ml) was treated with 10% methanolic NaOH (0.25 ml) and 30% H202 (1.6 ml) with stirring at room temperature for 16 hr. The resulting crystalline epoxide was filtered off, washed with cold methanol and dried. Recrystallization from methanol gave 700 mg (70% yield) ofllg, mp 108-1100 (lit. 108-llD°). lglgggggllggDiepo§yecholesta-4-ene-3-one 16) (a) With m-chloroperbenzoic acid: A solution of lg (400 mg, 1.0 mmole) in CHCl3 (10 ml) was treated with m-chloroperbenzoic acid (460 mg, 75.9% purity, 2.0 mmole), added in small portions with stirring until a clear solution was obtained. The mixture was stirred at room temperature for 12 hr. Solids were then collected on a filter and washed with a little CHCl3; and the filtrate, diluted with CHCl3 (50 ml), was washed with sodium bicarbonate (10%), water and brine; dried over anhydrous magnesium sulfate and taken to dryness under reduced pressure. After the addition of 5% ether solution in hexane (5 ml), crystalline lg precipitated from the solution. Filtration gave 70 mg of lg, and the filtrate was then purified by preparative TLC with 5% ether in hexane as the eluting solvent. Another 55 mg of lg was obtained (30% yield overall), mp 243-245°; IR (coc13) 1680 cm" at 250 nm (E3 23500); PMR (CDCl3) 63.33 (C7-H, dd, J6’7a4 Hz, ; UV maximum in methanol 25 J7,8=] Hz), 3.46 (C6-H, d, J6,7=4 Hz), 3.44 (CZ-H, dd,J]’2=4 Hz, J2.4=2 Hz), 3.53 (Cl-H, d, 01’284 Hz), 6.12 (C4-H, d, J =2 Hz); 2,4 MS (70 eV) m/e (rel. intensity) 412 (M+, 14), 396 (8), 95 (100). Anal. Calcd. for C27H4003 : C, 78.59; H, 9.77 Found : C, 78.59; H, 9.79 (b) By autoxidation: A solution of lg (190 mg, 0.48 mmole) in 2 ml of xylene was heated at 120-1300 in a flask equipped with a reflux condenser for 36 hr. Air was circulated through the refluxing solution. After removal of xylene in vacuo, the residue was separated by preparative TLC, using 8% ether in hexane as the eluting solvent. The principal uv-absorbing band was collected and eluted with ethyl acetate to give 40 mg of lg (21% yield). la,3“,7a-Cholesta-4-ene-triol (ll) (a) From la,2a.6¢,7a-diepoxy-cholesta-4-ene-3-one (lg): A solution of lg (412 mg, 1.0 mmole) in freshly distilled tetra- hydrofuran (20 ml) was treated with a suspension of lithium aluminum hydride (l g, excess) in freshly distilled tetrahydrofuran (20 ml) under gentle reflux for 9 hr. After decomposition of excess reagent with ethyl acetate (20 ml) in ether (50 ml), the mixture was poured into a saturated solution of potassium sodium tartrate, and the product was extracted with chloroform. Removal of solvent 26 and crystallization from 15% ethyl acetate in hexane afforded ll (255 mg, 61%) as needles, mp 178-1800; IR (c0013) 3550-3100 cm"; PMR (00013) 63.77 (Cy-H, d, 07’8sz Hz), 3.89 (CI-H, s), 4.15 (CB-H, s), 5.65 (C4-H, d, J85 Hz); MS (70 eV) m/e (rel. intensity) 418 (M+, 2), 400 (100), 382 (48), 367 (16), 364 (15). Anal. Calcd. for 627114603 : c, 77.46; H, 11.08 Found : C, 77.16; H, 10.97 (b) From 3a-acetoxy-la.26.66,7a-diepoxy-cholesta-4-ene (gg): A solution of gg (200 mg, 0.44 mmole) in freshly distilled tetra- hydrofuran (10 ml) was treated with a suspension of lithium alumina hydride (0.5 g, excess) in freshly distilled tetrahydro- furan (20 ml) under gentle reflux for 9 hr. After decomposition of excess reagent with ethyl acetate (10 ml) in ether (30 ml), the mixture was poured into a saturated solution of potassium sodium tartrate, and the product was extracted with chloroform. After the removal of solvent, the crude product was chromatographed on a silica gel, elution with 30% of ethyl acetate in hexane gave 110 mg (55%) of ll, identical in all respects with the product obtained from (a). 27 la,Za-Epgxy-au-hydroxy-cholesta-4,6-diene (lg) A solution of'lg (1.5 g, 3.79 mmole) in anhydrous methanol (200 ml) was treated with sodium borohydride (0.3 g, excess). This solution was stirred for 2 hr at room temperature, then neutralized with dil. acetic acid solution. Extraction with ether gave a colorless solid (1.5 g, quantitative yield). Recrystallization from methanol afforded lg (1.25 g, 83%) as needles, mp 98-990; IR (c014) 3500-3100 cm"; PMR (00013) 63.22 (CI-H, a, a] 2:4 Hz), 3.47 (CZ-H, quintet), 4.2 (C3-H, s), 5.15 (C4-H, s), 5.55 (CS-H, d, J6,7=10 Hz), 5.9 (C7-H, dd, J6,7‘]0 Hz, 07,882 Hz); MS (70 eV) m/e (rel. intensity) 398 (M+, 42), 380 (56), 365 (20), 95 (100). 33-Acetoxy:lg;g§-epoxy-cholesta-4,6-diene (lg) A solution of lg (1.15 g, 2.88 mmole) in dry pyridine (5 ml) was treated with acetic anhydride (10 m1, excess) and stirred under nitrogen at room temperature for 12 hr. After the usual work-up and recrystallization from methanol, lg, 1.066 g (92% yield) was obtained as colorless crystals, mp 106-1070; IR(CDC13) 1725 cm"; PMR (00013) 62.1 (3H, s), 3.2 (Cl-H, d, a, 2=5 Hz), 3.45 (CZ-H, quintet), 5.0 (C4-H, s), 5.58 (CG-H, d, J6.7-10 Hz), 5.73 (Ca-H, s), 5.85 (C7-H, dd, 06.7-10 Hz, J7,8=2 Hz); MS (70 eV) m/e (rel. intensity) 440 (M+, 3), 398 (6), 380 (34), 365 (40), 350 (24), 141 (100). 5921, Calcd. for C29H4403 : C, 79.04; H, 10.07 Found : C. 79.06; H, 10.11 28 §E:Acetoxy-la,20,60,7a-diepoxy-cholesta-4-ene (fig) A solution of lg (1.376 g, 3.13 mmole) in CHCl3 (30 ml) was treated with m-chloroperbenzoic acid (700 mg, 75.9% purity, 3.1 mmole) at 00 and stirred in an ice-water bath for two days under argon. Solids were then collected by filtration and washed with a little CHCl The filtrate, diluted with CHCl3 (80 ml), was 3. washed with sodium bicarbonate (10%), water and brine; dried over anhydrous magnesium sulfate and then taken to dryness under reduced pressure. Recrystallization from ethyl acetate yielded 890 mg (64% yield) of colorless crystals of £9, mp 201-203°; IR (00013) 1725 cm"; PMR (00013) 82.1 (3H, s), 3.13 (CI-H 8nd C7-H, d, J=4 Hz), 3.28 (CG-H, d, J6’784 Hz), 3.43 (CZ-H, quintet), 5.49 (C3-H, t, J2’38J3’482 Hz), 5.54 (C4-H, t, J2’4-J3,4-2 Hz); MS (70eV) m/e (rel. intensity) 456 (M+, 9), 414 (17), 396 (46 ). 380 (48), 365 (20), 350 (11), 132 (100). figgl, Calcd. for C29H4404 : C, 76.27; H, 9.71 Found : C, 76.46; H, 9.57 REFERENCES 11. 12. _9_1_, 3677 (1969). _3_c_1_, 880 (1947). REFERENCES a) M. Smith in "Reduction“, R. L. Augustine, Ed., Marcel Dekker, New York, N. Y., 1968. b) 0. Stork and S. D. Darling, J. Amer. Chem. Soc., 86, 1761 (1964). _ Z G. Stork, P. Rosen, N. Goldman, R. Coombs and J. Tsuji, ibid., g1, 275 (1965). P. S. Venkataramani and W. Reusch, Tet. Lett., 5283 (1968). William Reusch and D. B. Pridday, J. Amer. Chem. Soc., P. S. Venkataramani, J. E. Karoglan and W. Reusch, ibid., gg, 269 (1971). W. Reusch et a1., ibid., 22, 1953 (1977). D. B. Priddy, unpublished results from this lab. H. R. Taneja, Ph. D. dissertation, M. S. U. E. Glotter, M. Weissenberg and D. Lavie, Tetrahedron, 26, 3857 (1970). __. a) D. Swern, Chem. Rev., fig, 1 (1949). b) D. Swern, Organic Reacthns, Z, 378 (1953). c) D. Swern in D. Swern, ed., “OFganic Peroxides“, Vol.2, Wiley-Interscience, New York, .Y., 1971, Chapter 5. d) H. 0. House, “Modern Synthetic NReactions", 2nd ed. W. A. Benjamin, Menlo Park, Calif., 1972, Chapter 6. e) M. S. Malinovskii, ”Epoxides and Their Derivatives", Daniel Davey, New York. N. Y.. 1965. Y. R. Naves, 0. Schwarzkopf and A. D. Lewis, Helv. Chim. Acta., a) H. Sturzin er and P. Karrer, Helv. Chim. Acta., g2, 1829 (1946 . -- b) Y. Suhara and T. Minami, Bull. Chem. Soc. Jgg., 32, 169 (1966). -- c) S. Akagi and K. Tsuda, Chem. Pharm. Bull. (Tokyo),9 464 (1961). d) L. H. Knox, J. A. Zderic, J. P. Ruelas, C. Djerassi and H. J. Ringold, J. Amer. Chem. Soc., 82,1230 (1960). 29 13. 14. 15. 16. 17. 18. 19. 20. 21. 22. 30 a) P. A. Diassi, S. D. Levine and R. M. Palmere, J. Med. Chem., 19, 551 (1967). b) E. Farkas and JT—M. Owen, ibid., g, 510 (1966). A. Rosowsky in A. Weinberger, ed., "Heterocyclic Compounds with Three and Four Membered Rings", Part 1, Wiley- Interscience, New York, N. Y., 1964, Chapter 1. a) F. R. Mayo, Accounts of Chem. Res., 1, 193 (1968). b) W. G. Lloyd in E. S. Huyser, ed., ”MEthods in Free Radical Chemistry“, Vol. 3, Marcel Dekker, New York, N. Y., 1973, Chapter 1. G. H. Twigg, Chem. Eng, Sci., g, Suppl., 5 (1954) H. Hart and Paul B. Lavrik, J. Org. Chem., g2, 1793 (1974). A. B. Turner and H. J. Ringold, J. Chem. Soc. (c)., 1720 (1967). A. B. Turner, ibid., 2568 (1968). H. Y. Lam, H. K. Schnoes, H. F. DeLuca and L. Reeve, Steroids, 2g, 422 (1975). E. L. Eliel, N. L. Allinger, S. T. Angyral and G. A. Morrison, “Conformational Analysis", Wiley-Interscience, New York, N. Y., 1965, Chapter 5. N. S. Bhacca, D. H. Williams, "Applications of NMR Spectroscopy in Organic Chemistry --- Illustrations from the Steroids Field", Holden-Day, San Francisco, 1964, p. 19-23. APPENDIX 31 100 0 on O O TRANSMITTANCE(96) A O 20 . o _ V ' ‘ 4000 3500 3000 2500 2000 1500 FIEOUINC' (CM ') TRANSMITTANCE(%) 1800 1600 1400 1200 1000 800 "[000ch (CM '1 Figure 7. Infrared Spectrum of lg 32 100 A 0 on O O O TRANSMHTANCEWM N O o , 4000 3500 3000 2500 2000 1500 'IEOUENCV (CM ') TRANSMIITANCEWS) 2000 1800 l 600 1400 1200 1000 800 FREQUENCY (CM '1 Figure 8. Infrared Spectrum of ll TRANSMITTANCE(%) 33 1800 1600 1400 1200 1000 800 nloulucv ICM'I 100 80 ' . if 3 60 Z < .- Z a . z 40 < a: p— 20 0 H0' 4000 3500 3000 2500 2000 1500 magma (cm; Figure 9. Infrared Spectrum of lg 34 1500 .00 0 32—3.. 2500 2000 "£00940 (CM '1 3000 3500 —.—.g—._. _. “a.-- .. :51 w 2 z _ . 100 4000 Acimuzft 2325:. a A 6 4 msmuzitzmzép 1600 1400 1200 1000 800 "(00!ch (CM '1 1800 2000 Infrared Spectrum of lg Figure 10. 35 100 0 a) O O TRANSMITTANCE (73) In 0 20 O 4000 100 on O 0 O 4.1;; TRANSMITTANCE(%) h 0 20 O 2000 3500 1800 Figure 11. 3000 2500 moucucv (cm) 1400 1200 "10015an at» '1 1600 Infrared Spectrum of gg 2000 1500 800 Pelahv! 1310511617, Figure 13. Mass Spectrum of /lg 1 Li LL 1111 L L 37 I , ! “'1'. I" L L “SJ I! (“11' I! |LIL_L:L:.,___..J_ wfi 3.0 i” 3‘. J" i" "" Figure 14. Mass Spectrum of lg 80’ L574 113 . I} Q; pain" Figure 15. Mass Spectrum of ll 38 1:1 700:; 4} 311mm N Figure 16. Mass Spectrum of lg c ”0 luv 2 ' l ‘ .Ao"’ -= Figure 17. Mass Spectrum of gg N "11111111111111111(11111111171111191111111‘5