Synthesis of 3 beta,16 beta,19-trihydroxyandrost-5-en-17-one and 16 beta,19-dihydroxyandrost-4-ene-3,17-dione and their 19-oxo derivatives

3 beta,16 beta,19-Trihydroxyandrost-5-en-17-one (12) was synthesized from 5 alpha-bromo-3 beta-acetoxy-6 beta,19-epoxyandrostan-17-one (2) through acetoxylation at C-16 beta of the enol acetate 4 with lead tetraacetate and reductive cleavage of the epoxide ring with zinc dust yielding the 3 beta,16 beta-diacetoxy-19-hydroxy steroid 11, followed by hydrolysis of the acetoxy groups with sulfuric acid. Jones oxidation of compound 11 followed by the acid hydrolysis gave the 19-oxo steroid 15. 5 alpha-Bromo-3 beta-hydroxy-16 beta-acetoxy-6 beta,19-epoxyandrostan-17-one (8), obtained by selective hydrolysis of the 3-formate 5 with ammonium hydroxide, was oxidized with Jones reagent to afford the 3-oxo steroid 16, which was converted into the 19-hydroxy derivative 17 by treatment with zinc dust. 16 beta,19-Dihydroxyandrost-4-ene-3,17-dione (18) and its 19-oxo derivative 21 were obtained from compound 17 through a similar reaction sequence.     

The reactions of palladium(II), thallium(III) and lead(IV) trifluoroacetates with 3beta-acetoxyandrost-5-en-17-one: crystal structure of the first trifluoroacetate bridged 5,6,7-pi-allyl steroid palladium dimer

A number of metal trifluoroacetates were reacted with the olefin 3beta-acetoxyandrost-5-en-17-one (6). Palladium(II) trifluoroacetate afforded bis[micro-trifluoroacetato(alpha-5,7-eta-3beta-acetoxyandrostenyl-17-one)palladium(II)] (20), a new ring B pi-allyl steroid-palladium complex, in quantitative yield. Thallium(III) trifluoroacetate gave 3beta-acetoxy-5alpha-hydroxy-6beta-trifluoroacetoxyandrostan-17-one (16), 3beta-acetoxy-6beta-trifluoroacetoxyandrost-4-en-17-one (9), 3beta-acetoxy-4beta-trifluoroacetoxyandrost-5-en-17-one (10), and 3beta-acetoxy-5alpha,6beta-dihydroxyandrostan-17-one (17). Lead(IV) trifluoroacetate yielded 9, 10 and 16. 3beta-Acetoxy-5alpha,6beta-bis(trifluoroacetoxy)androstan-17-one (15), a new compound, was also formed in this reaction. During the course of the lead(IV) studies the dichlorosteroid 21 and the rearranged allylic oxidation product 24 were formed. Their formation was attributed to the generation of lead(IV) chloride in the reaction. Silver(I) and copper(II) trifluoroacetates proved to be unreactive towards 6.     

Specificity of Calreticulin Transacetylase to acetoxy derivatives of benzofurans: Effect on the activation of platelet Nitric Oxide Synthase

Calreticulin Transacetylase (CRTAase) catalyzes the transfer of acetyl group(s) from polyphenolic acetates (PAs) to functional proteins, such as Glutathione S-transferase (GST), NADPH Cytochrome c reductase and Nitric Oxide Synthase (NOS) resulting in the modulation of biological activities. A comparison of the specificities of the acetoxy derivatives of coumarins, biscoumarins, chromones, flavones, isoflavones and xanthones has been carried out earlier by us with an aim to study the effect of nature and position of the acetoxy groups on the benzenoid ring and the position of the carbonyl group with respect to oxygen/nitrogen heteroatom for the catalytic activity of CRTAase. In this communication for the first time, we have studied the influence of differently substituted benzofurans on the CRTAase activity to study the effect of the replacement of pyran ring of coumarin with furan ring, presence of carbonyl at C-3, substitution of C-3 carbonyl group with acetoxy group and presence of various substituents (OAc/OH/Cl) on the benzenoid ring. It was observed that acetoxy derivatives of benzofurans lead to inhibition of ADP induced platelet aggregation by the activation of platelet Nitric Oxide Synthase catalyzed by CRTAase. Accordingly, the formation of NO in platelets by 3-oxo-2,3-dihydrobenzofuran-6,7-diyl diacetate (3a) was found to be comparable with that of model polyphenolic acetate (PA), 7,8-diacetoxy-4-methylcoumarin (DAMC).     

Synthesis of 16 alpha,19-dihydroxy-4-androstene-3,17-dione and 3 beta,16 alpha,19-trihydroxy-5-androsten-17-one and their 17 beta-hydroxy-16-keto isomers

3 beta,16 alpha,19-Trihydroxy-5-androsten-17-one and 16 alpha,17-dihydroxy-4-androstene-3,17-dione were synthesized from the 5 alpha-bromo-6 beta,19-epoxy-17-ketone derivative 1, using the bromination at C-16 alpha of the 17-ketone 1 and the controlled alkaline hydrolysis of the 16 alpha-bromo-17-ketones 2 and 11 as key reactions. Zinc dust reductive cleavage of the 6 beta,19-epoxy-16 alpha-hydroxy-17-ketones 4 and 12, produced by controlled hydrolysis, gave the corresponding 19-alcohol derivatives 6 and 14, which were rearranged to the 17 beta-hydroxy-16-ketones 7 and 15 when treated with sodium hydroxide. The 3 beta,16 alpha,17 beta,19-tetrol 8 was obtained from the 16 alpha-ketol 6 by reaction with sodium borohydride.     

Studies on anabolic steroids--4. Identification of new urinary metabolites of methenolone acetate (Primobolan) in human by gas chromatography/mass spectrometry

The metabolism of methenolone acetate (17 beta-acetoxy-1-methyl-5 alpha-androst-1-en-3-one), a synthetic anabolic steroid, has been investigated in man. After oral administration of a 50 mg dose of the steroid to two male volunteers, twelve metabolites were detected in urine either in the glucuronide, sulfate or free steroid fractions. Methenolone, the parent steroid was detected in urine until 90 h after administration. Its cumulative urinary excretion accounted for 1.63% of the ingested dose. With the exception of 3 alpha-hydroxy-1-methylen-5 alpha-androstan-17-one, the major biotransformation product of methonolone acetate, metabolites were excreted in urine at lower levels, through minor metabolic routes. Most of methenolone acetate metabolites were isolated from the glucuronic acid fraction, namely methenolone, 3 alpha-hydroxy-1-methylen-5 alpha-androstan-17-one, 3 alpha-hydroxy-1 alpha-methyl-5 alpha-androstan-17-one, 17-epimethenolone, 3 alpha,6 beta-dihydroxy-1-methylen-5 alpha-androstan-17-one, 2 xi-hydroxy-1-methylen-5 alpha-androstan-3,17-dione, 6 beta-hydroxy-1-methyl-5 alpha-androst-1-en-3,17-dione, 16 alpha-hydroxy-1-methyl-5 alpha-androst-1-en-3,17-dione and 3 alpha,16 alpha-dihydroxy-1-methyl-5 alpha-androst-1-en-17-one. Interestingly, the metabolites detected in the sulfate fraction were isomeric steroids bearing a 16 alpha- or a 16 beta-hydroxyl group, whereas 1-methyl-5 alpha-androst-1-en-3,17-dione was the sole metabolite isolated from the free steroid fraction. Steroids identity was assigned on the basis of the mass spectral features of their TMS ether, TMS enol-TMS ether, MO-TMS, and d9-TMS ether derivatives and by comparison with reference and structurally related steroids. The data indicated that methenolone acetate was metabolized into several compounds resulting from oxidation of the 17-hydroxyl group and reduction of A-ring substituents, with or without concomitant hydroxylation at the C6 and C16 positions.     

An efficient synthesis of 5alpha-androst-1-ene-3,17-dione

5alpha-Androst-1-ene-3,17-dione (5) as a prodrug of 1-testosterone (4) was prepared in four steps from 17beta-Acetoxy-5alpha-androstan-3-one (stanolone acetate) (1) in high yield. Thus, stanolone acetate (1) was brominated in the presence of hydrogen chloride in acetic acid to give 17beta-acetoxy-2-bromo-5alpha-androstan-3-one (2), which underwent dehydrobromination using lithium carbonate as base with lithium bromide as an additive to give 17beta-acetoxy-5alpha-androst-1-en-3-one (3) in almost quantitative yield with 97% of purity. Compound (3) was hydrolyzed with sodium hydroxide to give 17beta-hydroxy-5alpha-androst-1-en-3-one (4,1-testosterone), which was oxidized with chromium trioxide to afford 5alpha-androst-1-ene-3,17-dione (5). The overall yield of 5 was 78.2% with purity of 99%. In this method, the formation of 4-ene was diminished when 1-ene was introduced, and its mechanism was also discussed.     

Calreticulin transacetylase: a novel enzyme-mediated protein acetylation by acetoxy derivatives of 3-alkyl-4-methylcoumarins

Our earlier investigations culminated in the discovery of a unique membrane-bound enzyme Calreticulin transacetylase (CRTAase) in mammalian cells catalyzing the transfer of acetyl group from polyphenolic acetates (PAs) to certain functional proteins viz. Glutathione S-transferase (GST), NADPH Cytochrome c reductase and Nitric oxide synthase (NOS) resulting in the modulation of their biological activities. In order to develop SAR study, herein, we studied the influence of alkyl group at C-3 position of acetoxy coumarins on the CRTAase activity. The alkylated acetoxy coumarins lead to inhibition of catalytic activity of GST, and ADP induced platelet aggregation by the way of activation of platelet Nitric oxide synthase (NOS). Furthermore, the increase in size of the coumarin C-3 alkyl group was found to decrease the CRTAase activity.     

Specificities of Calreticulin Transacetylase to acetoxy derivatives of 3-alkyl-4-methylcoumarins: Effect on the activation of nitric oxide synthase

Calreticulin Transacetylase (CRTAase) catalyzes the transfer of acetyl groups from polyphenolic acetates (PAs) to the receptor proteins and modulates their biological activities. CRTAase was conveniently assayed by the irreversible inhibition of cytosolic glutathione S-transferase (GST) by the model acetoxycoumarin, 7,8-diacetoxy-4-methylcoumarin (DAMC). We have studied earlier, the influence of acetoxy groups on the benzenoid ring, the effect of reduction of double bond at C-3 and C-4 position, the effect of methyl/phenyl group at C-4, and the influence of position of carbonyl group with respect to oxygen heteroatom in the benzopyran nucleus, for the catalytic activity of CRTAase. In this communication, we have extended our previous work; wherein we studied the influence of an alkyl group (ethyl, hexyl and decyl) at the C-3 position of the acetoxy coumarins on the CRTAase activity. The substitution at C-3 position of coumarin nucleus resulted in the reduction of CRTAase activity and related effects. Accordingly the formation of NO in platelets by C-3 alkyl substituted acetoxy coumarins was found to be much less compared to the unsubstituted analogs. In addition the alkyl substitution at C-3 position exhibited the tendency to form radicals other than NO.     

Studies on anabolic steroids--6. Identification of urinary metabolites of stenbolone acetate (17 beta-acetoxy-2-methyl-5 alpha-androst-1-en-3-one) in human by gas chromatography/mass spectrometry

The metabolism of stenbolone acetate (17 beta-acetoxy-2-methyl-5 alpha-androst-1-en-3-one), a synthetic anabolic steroid, has been investigated in man. Nine metabolites were detected in urine either as glucuronic or sulfuric acid aglycones after oral administration of a single 50 mg dose to a male volunteer. Stenbolone, the parent compound, was detected for more than 120 h after administration and its cumulative excretion accounted for 6.6% of the ingested dose. Most of the stenbolone acetate metabolites were isolated from the glucuronic acid fraction, namely: stenbolone, 3 alpha-hydroxy-2-methyl-5 alpha-androst-1-en- 17-one, 3 alpha-hydroxy-2 xi-methyl-5 alpha-androst-17-one; 3 isomers of 3 xi, 16 xi-dihydroxy-2-methyl-5 alpha-androst-1-en-17-one; 16 alpha and 16 beta-hydroxy-2-methyl-5 alpha-androst-1-ene-3, 17-dione; and 16 xi, 17 beta-dihydroxy-2-methyl-5 alpha-androst-1-en-3-one. Only isomeric metabolites bearing a 16 alpha or a 16 beta-hydroxyl group were detected in the sulfate fraction. Interestingly, no metabolite was detected in the unconjugated steroid fraction. The steroids identities were assigned on the basis of their TMS ether, TMS enol-TMS ether, MO-TMS and d9-TMS ether derivatives and by comparison with reference and structurally related steroids. Data indicated that stenbolone acetate was metabolized into several compounds resulting from oxidation of the 17 beta-hydroxyl group and/or reduction of A-ring delta-1 and/or 3-keto functions with or without hydroxylation at the C16 position. Finally, comparison of stenbolone acetate urinary metabolites with that of methenolone acetate shows similar biotransformation pathways for both delta-1-3-keto anabolic steroids. This indicates that the position of the methyl group at the C1 or C2 position in these steroids has little effect on their major biotransformation routes in human, to the exception that stenbolone cannot give rise to metabolites bearing a 2-methylene group since its 2-methyl group cannot isomerize into a 2-methylene function through enolization of the 3-keto group as previously observed for methenolone.     

Microbiologic oxidation of estratrienes and estratetraenes by Streptomyces roseochromogenes ATCC 13400

Incubation of estrone (1a) with Streptomyces roseochromogenes ATCC 13400 yielded a mixture of 3,16 alpha-dihydroxyestra-1,3,5(10)-trien-17-one (3a) and 3,17 beta-dihydroxyestra-1,3,5(10)-trien-16-one (4a). Transformation of 3-methoxyestra-1,3,5(10)-trien-17-one (1b), 3-hydroxyestra-1,3,5(10),9(11)-tetraen-17-one (2a), and 3-methoxyestra-1,3,5(10),9(11)-tetraen-17-one (2b) with the same microorganism gave the corresponding mixtures of 16 alpha-hydroxy-17-ketones and 17 beta-hydroxy-16-ketones (3b and 4b, 6a and 7a, 6b and 7b, respectively). In addition, in these three last experiments, the 16 beta-17 beta-dihydroxy derivatives 5b, 8a, and 8b, respectively, were also isolated. The complete assignments of the 13C nuclear magnetic resonance spectra of these compounds are given.     

Stereoselective reduction of C-2 substituted steroid C-3 ketones with lithium tris-(R,S-1,2-dimethylpropyl)-borohydride and sodium borohydride

The effect of C-2 substitution on the stereoselective reduction of steroid C-3 ketones with lithium tris-(R,S-1,2-dimethylpropyl)-borohydride and sodium borohydride was investigated. The C-2 mono- and di-substituted chloro and methyl derivatives were predominantly reduced to one of the epimeric alcohols. The 2 alpha-chloro and 2 alpha-methyl derivatives of 17 beta-acetoxy-5 alpha-androstan-3-one undergo stereoselective reduction with lithium tris-(R,S-1,2-dimethylpropyl)-borohydride to the axial (3 alpha) alcohol as observed in the unsubstituted compound, whereas sodium borohydride gives predominantly the equatorial (3 beta) alcohol. The 2 beta-chloro, 2 beta-methyl, 2,2-dichloro, and 2,2-dimethyl derivatives are reduced predominantly to the equatorial (3 beta) alcohol by both reagents.     

Mechanism of biochemical action of substituted benzopyran-2-ones. Part 8: Acetoxycoumarin: protein transacetylase specificity for aromatic nuclear acetoxy groups in proximity to the oxygen heteroatom

Our earlier work established a convenient assay procedure for acetoxycoumarin (AC): protein transacetylase (TA) by indirectly quantifying the activity of glutathione (GSH)-S-transferase (GST), the extent of inhibition of GST under the conditions of the assay represented TA activity. In this communication, we have probed the specificity for TA with respect to the number and position of acetoxy groups on the benzenoid as well as the pyranone rings of the coumarin system governing the efficient transfer of acetyl groups to the protein(s). For this purpose, coumarins bearing one acetoxy group, separately at C-3 or C-4 position and 4-methylcoumarins bearing single acetoxy group, separately at C-5, C-6 or C-7 position were synthesized and specificities to rat liver microsomal TA were examined. Negligible TA activity was discernible with 3-AC as the substrate, while the substrate efficiency of other AC were in the order 7-acetoxy-4-methylcoumarin (7 AMC)>6 AMC>5 AMC=5 ADMC=4 AC. To achieve a comparable level of GST inhibition which was proportional to the enzymatic transfer of acetyl groups to the protein (GST), the concentrations of 7-AMC, 6-AMC, 5-AMC and 4-AC were in the order 1:2:4:4, respectively. One diacetoxycoumarin, i.e., 7,8-diacetoxy-4-methylcoumarin (DAMC) was also examined and it was found to elicit maximum level of GST inhibition, nearly twice that observed with 7-AMC. These observations lead to the logical conclusion that a high degree of acetyl group transfer capability is conferred when the acetoxy group on the benzenoid ring of the coumarin system is in closer proximity to the oxygen heteroatom, i.e., when the acetoxy groups are at the C-7 and C-8 positions.     

Efficient preparation of steroidal 5,7-dienes of high purity.

Protected forms of dehydroepiandrosterone, delta 5 cholenic acid, (25R)-26-hydroxycholesterol and diosgenin were converted to the corresponding delta 5,7 dienes by successive treatment with 1,3-dibromo-5,5-dimethylhydantoin (dibromantin), tetrabutylammonium bromide and tetrabutylammonium fluoride. The crude products, which contained the delta 5,7 species contaminated by minor amounts of the delta 5 and delta 4,6 steroids, were purified by silica gel-AgNO3 chromatography to give the following steroids in approximately 99% purity and at least 50% yield: 3 beta-acetoxyandrosta-5,7-dien-17-one, methyl 3 beta-acetoxychola-5,7-dien-24-oate, (25R)-3 beta,26-diacetoxycholesta-5,7-diene and (25R)-3 beta-acetoxyspirosta-5,7-diene. Analogous treatment of acetate derivatives of pregnenolone and stigmasterol gave 3 beta-acetoxypregna-5,7-dien-20-one and 3 beta-acetoxystigmasta-5,7,22-triene in approximately 50% yield but of lower purity. Full 1H and 13C NMR assignments are given for seven delta 5,7 steroid acetates and the corresponding delta 5 starting materials. Coupling constants for rings A, B and C of delta 5,7 steroids are presented and stereochemical assignments have been made for the following 1H NMR signals: the C-11 protons of delta 5,7 steroids, the C-16 protons of sterols and bile acids, the C-22 and C-23 protons of bile acid esters and the C-28 protons of stigmasterol derivatives.     

Mechanism of biochemical action of substituted 4-methylbenzopyran-2-ones. Part 9: comparison of acetoxy 4-methylcoumarins and other polyphenolic acetates reveal the specificity to acetoxy drug: protein transacetylase for pyran carbonyl group in proximity to the oxygen heteroatom

The evidences for the possible enzymatic transfer of acetyl groups (catalyzed by a transacetylase localized in microsomes) from an acetylated compound (acetoxy-4-methylcoumarins) to enzyme proteins leading to profound modulation of their catalytic activities was cited in our earlier publications in this series. The investigations on the specificity for transacetylase (TA) with respect to the number and positions of acetoxy groups on the benzenoid ring of coumarin molecule revealed that acetoxy groups in proximity to the oxygen heteroatom (at C-7 and C-8 positions) demonstrate a high degree of specificity to TA. These studies were extended to the action of TA on acetates of other polyphenols, such as flavonoids and catechin with a view to establish the importance of pyran carbonyl group for the catalytic activity. The absolute requirement of the carbonyl group in the pyran ring of the substrate for TA to function was established by the observation that TA activity was hardly discernible when catechin pentacetate and 7-acetoxy-3,4-dihydro-2,2-dimethylbenzopyran (both lacking pyran ring carbonyl group) were used as the substrates. Further, the TA activity with flavonoid acetates was remarkably lower than that with acetoxycoumarins, thus suggesting the specificity for pyran carbonyl group in proximity to the oxygen heteroatom. The biochemical properties of flavonoid acetates, such as irreversible activation of NADPH cytochrome C reductase and microsome-catalyzed aflatoxin B₁ binding to DNA in vitro were found to be in tune with their specificity to TA.     

Studies on Baeyer–Villiger oxidation of steroids: DHEA and pregnenolone d-lactonization pathways in Penicillium camemberti AM83

Penicillium camemberti AM83 strain is able to carry out effective Baeyer–Villiger type oxidation of DHEA, pregnenolone, androstenedione and progesterone to testololactone. Pregnenolone and DHEA underwent oxidation to testololactone via two routes: through 4-en-3-ketones (progesterone and/or androstenedione respectively) or through 3β-hydroxy-17a-oxa-d-homo-androst-5-en-17-one.Analysis of transformation progress of studied substrates as function of time indicates that the 17β-side chain cleavage and oxidation of 17-ketones to d-lactones are catalyzed by two different, substrate-induced, BVMOs. In the presence of a C-21 substrate (pregnenolone or progesterone) induction of the enzyme catalyzing cleavage at 17β-acetyl chain was observed, whereas DHEA and androstenedione induced activity of the BVMO responsible for the ring-D oxidation; 5-en-3β-alcohol was a more effective inducer that the respective 4-en-3-ketone.     

An efficient procedure for the regiospecific preparation of D-homo-steroid derivatives

alpha-Diazo-beta-hydroxy esters 3, obtained by condensation of ketones 1 with ethyl diazo(lithio)acetate 2, are efficiently converted into the corresponding beta-ketoesters 4 by exposure to dirhodium (II) tetraacetate. Application of this two-step sequence to 3 beta-acetoxy-5-androstene-17-one 5b and to 3-acetoxy estrone 10b afforded regiospecifically and in very high overall yield the corresponding ethyl 17a-oxo-D-homo-steroid-17-carboxylates 7a,b and 12a,b, which were decarboalkoxylated to give, respectively, 3 beta-hydroxy-D-homo-5-androstene-17a-one 8 and D-homoestrone 13.     

An NMR technique for carbon-5 configurations in 6-keto-delta7-steroids

Enol acetates may be readily prepared from 6-keto-Δ⁷-steroids, The NMR examination of the C-7 proton allows assessment of the allylic coupling to the C-5 proton. If split into a doublet, then the C-5 configuration is α; if a singlet, then C-5 is β. The configuration at C-5 in the initial ketone is preserved in the enol acetate.     

Isolation and structure elucidation of new radical oxidation products of 5-hydroxy steroids

Three new products have been isolated from the lead-tetraacetate version of the hypoiodite oxidation of 3beta,17beta-diacetoxy-5-hydroxy-5 alpha-androstane. Along with the expected 1(10)-unsaturated 5,10-seco steroidal 5-ketones, the fragmentation reaction gave two epimeric C-4 iodides. Their structural assignment was based on X-ray data of one of them ((4R,10S)-4-iodo-3beta,17beta-diacetoxy-5,10-secoandrostan-5-one). The third new product was found to be the 5 beta,6 beta-epoxide resulting from the dehydration of the tertiary alcohol followed by epoxidation of the intermediate Delta(5)-olefin.     

Inhibitors of sterol synthesis. Synthesis and spectral properties of 3 beta-hydroxy-24-dimethylamino-5 alpha-chol-8(14)-en-15-one and its effects on HMG-CoA reductase activity in CHO-K1 cells.

A simple, three-step synthesis of the 25-aza analog of 3 beta-hydroxy-5 alpha-cholest-8(14)-en-15-one (I) is described. Treatment of 3 beta-acetoxy-24-hydroxy-5 alpha-chol-8(14)-en-15-one (III) with 1.75 equivalents of tosyl chloride in pyridine for 24 h at 5 degrees C gave 3 beta-acetoxy-24-tosyloxy-5 alpha-chol-8(14)-en-15-one (IV). In contrast, treatment of III with 3.95 equivalents of tosyl chloride in pyridine for 12 h at 48 degrees C gave 3 beta-acetoxy-24-chloro-5 alpha-chol-8(14)-en-15-one (V). Treatment of IV with dimethylamine in dioxane yielded 3 beta-acetoxy-24-dimethylamino-5 alpha-chol-8(14)-en-15-one (VI). Hydrolysis of VI with LiOH.H2O in methanol gave 3 beta-hydroxy-24-dimethylamino-5 alpha-chol-8(14)-en-15-one (VII). 1H- and 13C-NMR assignments are presented for compounds IV-VII. The 25-aza analog (VII) of the 15-ketosterol (I), at a concentration of 1.0 microM, caused a 47% lowering of the level of 3-hydroxy-3-methylglutaryl coenzyme A reductase activity in Chinese hamster ovary cells.     

The effect of 4beta and 19 ester functionalities on some electrophilic addition reactions of delta5-steroids

The reactions of 3beta-acyloxyandrost-5-enes with bromine/silver acetate (Petrow reaction) and mercury(II) trifluoroacetate (modified Treibs oxidation) have been used previously to effect allylic oxidation on these substrates en route to biologically active compounds. In both these reactions, which involve electrophilic addition to the delta5-bond, the 3-acyloxy substituent plays a significant role. In this report, the effect of introducing other substituents proximate to the delta5-bond has been studied by using derivatives of 3beta-acetoxyandrost-5-en-17-one (1), namely, 3beta,4beta-diacetoxyandrost-5-en-17-one (13), 3beta,19-diacetoxyandrost-5-en-17-one (14), 3beta-acetoxyandrost-5-ene-7,17-dione (15), and 3beta-acetoxy-4,4-dimethylandrost-5-en-17-one (17). Our results indicate that in both sets of reactions the effect of the introduced functional groups was pronounced. In the Petrow reaction, electrophilic addition rather than allylic oxidation on the diacetates was observed. With the Treibs reaction, allylic oxidation on the diacetates occurred. The 7-keto and 4,4-dimethyl steroids proved to be poor substrates in both reactions.