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Suzuki coupling of 17-iodoandrosta-5,16-dien-3beta-ol (1) and 17-iodoandrosta-4,16-dien-3-one (2) with nine heteroaryl boronic acids (mainly 2- or 3-furanyl, thienyl, benzofuranyl and benzothienyl boronic acid derivatives) were carried out under normal Suzuki condition (Pd(PPh(3))(4), 2M Na(2)CO(3) and MeOH), generally yielded C(17)-heteroaryl steroids in moderate (10-60%) yields, but furanyl-2- and 5-chlorothienyl-2-boronic acid did not give any coupling product.

Twelve 17-(2'-oxazolyl)- and 17-(2'-thiazolyl)-androsta-5,16-diene derivatives were designed and synthesized from 3 beta-acetoxy-pregna-5,16-dien-20-one (1b) as inhibitors of 17 alpha-hydroxylase-C(17,20)-lyase (P450(17 alpha)). Potent inhibitors of this enzyme could be of value as treatment of prostate cancer. Two substituents (methyl and phenyl) were introduced either at their 4'- or 5'-position in order to investigate their structure-activity relationship. Due to the 16,17-double bond, 17-thiazoles were generally obtained in low yield. The pharmacological results showed that the compounds containing 17-(2'-oxazolyl) (14c) and 17-(2'-thiazolyl) (8c) (41.5%) demonstrated reasonable inhibition against P450(17 alpha). Their 3-acetate (13c and 7c) were less potent than their 3-OH counterparts. The introduction of a phenyl or methyl group generally decreased inhibitory activity. Surprisingly, 17-(5'-methyl-2'-thiazolyl) (12a) was the most potent compound in this series and was almost as potent as L-39, which has good antitumor activity.

The preparation of 17beta-substituted 14beta-hydroxysteroid C-3 alpha-L-rhamnopyranosides is described. These derivatives have a 14beta,20-ether, 14beta,20-lactone, or 17beta-CH2CH2OH, -CH2CH2NH2, -CH=CHNO2(E), -CH=CHCOOH(E), -CH(OH)CH2NO2(R), -CH(OMe)CH2NO2(R), -CH2-CH2COOH, or -CH(OH)CH2NH2(R) group. Derivatives were assayed in a radioligand binding assay for [3H]ouabain in membranes from canine heart muscle. The digitalis "receptor" comprises isoenzymes of the ion-pumping enzyme, Na+,K+-ATPase. The 17beta-CH=CHNO2(E), 17beta-CH=CHCOOH(E), and 17beta-CH(OMe)CH2NO2(R) derivatives were the most potent and equivalent to ouabain with low-nanomolar IC50 values. The very potent binding affinity of the disubstituted compound 17beta-CH(OMe)CH2NO2(R) further demonstrates that 17beta-unsaturated substitution is not required for potent binding affinity. This observation may be of value in the separation of cardiotonic and cardiotoxic effects. Tosylation of the 17beta-CH2OH, prepared from the 17beta-CHO by lithium aluminum hydride reduction, yielded the 14beta,17beta-ether. Synthesis of the 17beta-CH2COOH gave the epimeric 14alpha,17alpha- and 14beta,17beta-lactones. Structures have been established by NMR analysis.

19(R/S)-Hydroxy-5β,19-cyclosteroids have been synthesised from the 19-formyl 4-en-3-one by reductive cyclization with zinc in aqueous acetic acid. Treatment of the aldehyde with lithium in liquid ammonia also gave the 19(R)-hydroxy-5β,19-cyclosteroid together with the 17β-hydroxy analogue. The 19(R)-alcohol is isomerized to the 19(S)-alcohol in either dilute acidic or basic media via the 3-hydroxy-3,5-cyclosteroid. The 19(S)-alcohol is in equilibrium with its 3-hemiketal. Treatment of the 19(R)-alcohol with methanolic HCl gave the 19(R)- and 19(S)-methyl ethers, the 3-methyl ether 19-ketal and the 3α-methoxy-3β,5β- cyclosteroid. Further rearrangements of the 19(R)- and 19(S)-alcohols take place on more vigorous treatment with acid or base to give cyclopropanol ring-opened aldehydes including a 5β-methyl-A-norsteroid. Metal hydride reduction of the 3-ketone in the 19(R)-alcohol gave only the 3β-alcohol whereas the 19(S)-alcohol gave both the 3α- and 3β-alcohols. Acid treatment of the 3β-alcohols gave products with retention of configuration at C-5 and C-19 while base-catalysed ring opening gave inversion at C-5. Ring opening mainly involved breaking of the 5,19-bond, however, the 19(S)-alcohol also resulted in 10,19-bond cleavage. Structures were established by NMR measurements.

Dexrazoxane (ICRF-187) is clinically used to reduce doxorubicin-induced cardiotoxicity. Because dexrazoxane, doxorubicin and daunorubicin all act on DNA topoisomerase II, a study was undertaken to see what effect dexrazoxane had on the growth inhibitory effects of doxorubicin and daunorubicin towards Chinese hamster ovary cells. Dexrazoxane exhibited significant antagonism of doxorubicin- and daunorubicin-mediated growth inhibition when the cells were preincubated with dexrazoxane before the anthracycline was added. Continuous exposure of cells to either anthracycline and low concentrations of dexrazoxane resulted in additive growth inhibitory effects at low anthracycline concentrations, and no effect at higher anthracycline concentrations.

Proton and carbon NMR data are provided for 21 ring A and ring B cyclosteroids and cyclopropano (or methylene) steroids. Shift assignments were made using standard 2D NMR techniques, while ring A proton subspectra were extracted with a 1D TOCSY experiment. Coupling constants were obtained from iterative spin system simulation of these sub-spectra. Ring A conformations were determined from the two- and three-bond proton-proton couplings and NOE measurements. The utility and limitations of extended Karplus-type equations, the effect of cyclopropyl groups on vicinal and geminal couplings and cyclopropane-induced chemical shifts are discussed.

Synthesis of 19(R/S)-hydroxy-5β,19-cycloandrostane-3,17-dione by reductive cyclization of the steroid 4-en-3-one 19-aldehyde with zinc in aqueous acetic acid is reported. On either acid or base treatment the R-isomer is converted to the S-isomer through an intermediate 3-hydroxy-3,5-cyclosteroid.

14β-Hydroxy-5β-pregnane and 14β-hydroxy-21-nor-5β-pregnane derivatives of ouabain were synthesised and their structures established by NMR measurements. Binding affinity in an [ 3 H]ouabain radioligand binding assay was determined. Pregnane derivatives of ouabain are more polar than pregnane rhamnoside derivatives of digitoxigenin. Whereas ouabain binds similarly to digitoxigenin rhamnoside, the pregnane derivatives of ouabain have significantly weaker binding affinity than their congeners from digitoxigenin.

Coupling constants and nuclear Overhauser effect measurements were used to establish the C-20 configuration and the conformation about the C-17C-20 bond in a series of sixteen C-20-substituted 5β,14β-pregn-14-enes. In the 14β-pregnane series the conformation of the C-17 side-chain is variable, whereas in the pregnenes the side-chain adopts a conformation in which H-17 is anti to H-20. The C-17 side-chain conformation of two 21-nor-5β,14β-pregnanes was also determined. In the 21-nor compounds a C-20 hydroxyl adopts a conformation anti to H-17, while a C-20 nitro group is anti to C-13.

Ozonolysis of digitoxin, digitoxin tetraacetate, digitoxin tetrakis-(2,2,2-trichloroethyl carbonate), digitoxigenin, digitoxigenin acetate, digitoxigenin hemisuccinate and digitoxigenin 2,2,2-trichloroethyl carbonate followed by treatment with excess of zinc in acetic acid gave either the corresponding 21-hydroxy ester after 5 min or the 21-methyl ketone after 20 h. This procedure is more efficient than methods previously reported for the conversion of the α,β-unsaturated γ-lactone into an acetyl group and is applicable to the cardiac glycosides directly to give 14β-hydroxypregnan-20-one derivatives. Acidic hydrolysis of 14,21-dihydroxy-and 14-hydroxy-3β-tris(digitoxosyloxy)-5β,14β-pregnan-20-one is reported. Structures are based on 1H and 12C NMR assignments.

Synthesis of 20α- and 20β-acetamido-, amino-, nitro- and hydroxy-3β-glycoside (α-L-rhamnopyranoside and tris-β-D-digitoxoside) and genin derivatives of 14-hydroxy-5β,14β-pregnane together with the C-20 oxime, hydrazone and amidinohydrazone is described from digitoxin. Ortho esters were also isolated. Structures were established by NMR measurements. These compounds have been shown to bind to the digitalis receptor of heart muscle. The 20β derivatives were consistently more potent than are the corresponding 20α compounds. The 20β-nitro α-L-rhamnoside derivative proved to be the most potent. Receptor binding data are given and structure-activity relationships are presented.

Novel insertion, rearrangement and addition products from dibromocarbene and dichlorocarbene reactions with 5(10)-unsaturated steroids have been identified. The dihalogenocarbenes were prepared under phase-transfer conditions (CHBr3– or CHCl3–NaOH), and from CHBr3–KOBut–Et2O, phenyl(trichloromethyl)mercury and sodium trichloroacetate. Evidence that the major products arise from an initial dihalogenocarbene reaction on the α face of the molecule is reported. The major products obtained from addition of CBr2 to 3,17-disubstituted estr-5(10)-enes, after ketal hydrolysis, were 19(S)-bromo-9α,19-cyclo-10α-androst-4-en-3-one and 3,′3′,19(S)-tribromo-3′H-9α,19-cyclocyclopropa[5,6]-5β, 10α-androstan-3-one derivatives together with the 19,19-dibromo-5α,19-cyclo-10α-steroid adduct. No products from addition of CBr2 to the β face of the double bond, as previously reported, were identified. Reactions of CCl2 gave, besides rearrangement products analogous to those obtained from CBr2, a 5α-hydroxy-9α,19α-cycloandrostane derivative, the 9α-CHCl2 insertion derivative and both α- and β-face addition products to the double bond. Structures were established by homonuclear and heteronuclear correlation and nuclear Overhauser effect NMR measurements and X-ray crystallography.

Synthesis of 19(R/S)-hydroxy-5β,19-cycloandrostane-3,17-dione by reductive cyclization of the steroid 4-en-3-one 19-aldehyde with zinc in aqueous acetic acid is reported. On either acid or base treatment the R-isomer is converted to the S-isomer through an intermediate 3-hydroxy-3,5-cyclosteroid.

19(R/S)-Hydroxy-5β,19-cyclosteroids have been synthesised from the 19-formyl 4-en-3-one by reductive cyclization with zinc in aqueous acetic acid. Treatment of the aldehyde with lithium in liquid ammonia also gave the 19(R)-hydroxy-5β,19-cyclosteroid together with the 17β-hydroxy analogue. The 19(R)-alcohol is isomerized to the 19(S)-alcohol in either dilute acidic or basic media via the 3-hydroxy-3,5-cyclosteroid. The 19(S)-alcohol is in equilibrium with its 3-hemiketal. Treatment of the 19(R)-alcohol with methanolic HCl gave the 19(R)- and 19(S)-methyl ethers, the 3-methyl ether 19-ketal and the 3α-methoxy-3β,5β- cyclosteroid. Further rearrangements of the 19(R)- and 19(S)-alcohols take place on more vigorous treatment with acid or base to give cyclopropanol ring-opened aldehydes including a 5β-methyl-A-norsteroid. Metal hydride reduction of the 3-ketone in the 19(R)-alcohol gave only the 3β-alcohol whereas the 19(S)-alcohol gave both the 3α- and 3β-alcohols. Acid treatment of the 3β-alcohols gave products with retention of configuration at C-5 and C-19 while base-catalysed ring opening gave inversion at C-5. Ring opening mainly involved breaking of the 5,19-bond, however, the 19(S)-alcohol also resulted in 10,19-bond cleavage. Structures were established by NMR measurements.

19(R/S)-Substituted 1β,19-cyclo-5α-steroids have been synthesized by reductive cyclization of 3,17-dioxo-5α-androst-1-en-19-al with zinc in aqueous acetic acid or lithium in ammonia. The major product from the zinc reaction, the 19(R)-cyclopropanol, exists in equilibrium with the 3-hemiketal; the minor product, the 19(S)-alcohol, is isolated as the silyl ether and deprotected to give the 19(S)-cyclopropanol. The major product from the lithium–ammonia reaction is the 19(S)-cyclopropanol. Neither acid nor base treatment of the 19(R)- and 19(S)-alcohols gives evidence of their interconversion. Structures are established by NMR measurements.

Synthesis of 20α- and 20β-acetamido-, amino-, nitro- and hydroxy-3β-glycoside (α-L-rhamnopyranoside and tris-β-D-digitoxoside) and genin derivatives of 14-hydroxy-5β,14β-pregnane together with the C-20 oxime, hydrazone and amidinohydrazone is described from digitoxin. Ortho esters were also isolated. Structures were established by NMR measurements. These compounds have been shown to bind to the digitalis receptor of heart muscle. The 20β derivatives were consistently more potent than are the corresponding 20α compounds. The 20β-nitro α-L-rhamnoside derivative proved to be the most potent. Receptor binding data are given and structure-activity relationships are presented.

Ozonolysis of digitoxin, digitoxin tetraacetate, digitoxin tetrakis-(2,2,2-trichloroethyl carbonate), digitoxigenin, digitoxigenin acetate, digitoxigenin hemisuccinate and digitoxigenin 2,2,2-trichloroethyl carbonate followed by treatment with excess of zinc in acetic acid gave either the corresponding 21-hydroxy ester after 5 min or the 21-methyl ketone after 20 h. This procedure is more efficient than methods previously reported for the conversion of the α,β-unsaturated γ-lactone into an acetyl group and is applicable to the cardiac glycosides directly to give 14β-hydroxypregnan-20-one derivatives. Acidic hydrolysis of 14,21-dihydroxy-and 14-hydroxy-3β-tris(digitoxosyloxy)-5β,14β-pregnan-20-one is reported. Structures are based on 1H and 12C NMR assignments.

5 alpha-pregnane-3 beta,14 beta,20 beta-triol 3-alpha-L-rhamnopyranoside (8) and 3 beta-(alpha-L-rhamnopyranosyloxy)-5 alpha-pregn-14-en-20-one (14) were prepared from uzarigenin by ozonolysis followed by zinc and acetic acid reduction and glycosidation. During the glycosidation reaction leading to (8) the corresponding ortho ester (9) was also obtained. Uzarigenin alpha-L-rhamnopyranoside (15) also was prepared. Synthesis of 5 alpha-pregnane-3 beta,14 beta,20 beta-triol (20) is described. Structures were established by analysis of their NMR spectra. The binding affinity of 5 alpha and 5 beta cardenolide and pregnane derivatives as measured in a radioligand binding assay was determined and their structure-activity relationships compared. The receptor binding affinity of the 5 alpha derivatives is less than that of the corresponding 5 beta derivatives.

The preparation of derivatives of 14-hydroxy-21-nor-5 beta,14 beta-pregnane and 5 beta,14 beta-pregnane C-3 alpha-L-rhamnosides and tris-beta-D-digitoxosides is described. These derivatives, possessing a C-17 beta COCH2OH, CH2OH, CO2H, CO2Me, CH2NH2, or CH2NO2 group, bind to the digitalis receptor recognition site of heart muscle as measured in a radioligand binding assay. The 21-norpregnane derivatives consistently show greater binding affinity than the corresponding 20 alpha- and 20 beta-pregnane analogs. The C-20 nitro rhamnoside is comparable to digitoxin in binding affinity. The 17 beta-CH2NO2 group is the most effective replacement for the unsaturated lactone in the binding assay found so far, showing binding affinity comparable to that of the cardiac glycosides.

Novel insertion, rearrangement and addition products from dibromocarbene and dichlorocarbene reactions with 5(10)-unsaturated steroids have been identified. The dihalogenocarbenes were prepared under phase-transfer conditions (CHBr3– or CHCl3–NaOH), and from CHBr3–KOBut–Et2O, phenyl(trichloromethyl)mercury and sodium trichloroacetate. Evidence that the major products arise from an initial dihalogenocarbene reaction on the α face of the molecule is reported. The major products obtained from addition of CBr2 to 3,17-disubstituted estr-5(10)-enes, after ketal hydrolysis, were 19(S)-bromo-9α,19-cyclo-10α-androst-4-en-3-one and 3,′3′,19(S)-tribromo-3′H-9α,19-cyclocyclopropa[5,6]-5β, 10α-androstan-3-one derivatives together with the 19,19-dibromo-5α,19-cyclo-10α-steroid adduct. No products from addition of CBr2 to the β face of the double bond, as previously reported, were identified. Reactions of CCl2 gave, besides rearrangement products analogous to those obtained from CBr2, a 5α-hydroxy-9α,19α-cycloandrostane derivative, the 9α-CHCl2 insertion derivative and both α- and β-face addition products to the double bond. Structures were established by homonuclear and heteronuclear correlation and nuclear Overhauser effect NMR measurements and X-ray crystallography.