- Zinc(II)-promoted Stereospecific Rearrangement of 17-Hydroxy-20-oxopregnane Derivatives
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A new and highly efficient method for D-homo-rearrangements in the steroid field is described.The transformation is induced by the action of zinc(II) on different 17-hydroxy-20-oxopregnanes.With 17α-hydroxy-20-oxopregnanes the reaction afforded 17aα-hydroxy-17aβ-methyl-D-homo-derivatives while under the same conditions 17β-hydroxy-20-oxopregnanes gave the corresponding 17a-epimeric-D-homo-steroids.In both cases the rearrangement was stereospecific giving the corresponding products in almost quantitative yields.
- Schor, Laura,Seldes, Alicia M.,Gros, Eduardo G.
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- One-pot ethynylation and catalytic desilylation in synthesis of mestranol and levonorgestrel
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A one-pot ethylnylation and catalytic desilylation reaction was developed for the synthesis of mestranol and levonorgestrel. Addition of trimethylsilylacetylide to the carbonyl group at C-17 of the steroids yielded the C-17α-trimethylsilylacetylenyl adducts, which were desilylated with a catalytic amount of TBAF (0.050 equiv) in one pot to provide the corresponding mestranol and levonorgestrel both in 90% yields. A plausible mechanism was proposed for the catalytic desilylation through the regeneration of the fluoride ion from the reaction of alkoxide on the steroid with Me3SiF. The one-pot ethynylation and catalytic desilylation methodology provided an alternative route and avoided the traditional use of flammable and explosive acetylene gas toward the synthesis of mestranol and levonorgestrel.
- Wong, Fung Fuh,Chuang, Shih Hsien,Yang, Sheng-chuan,Lin, Yu-Hsiang,Tseng, Wen-Che,Lin, Shao-Kai,Huang, Jiann-Jyh
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supporting information; experimental part
p. 4068 - 4072
(2010/07/05)
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- METHODS FOR PREPARING 17-ALKYNYL-7-HYDROXY STEROIDS AND RELATED COMPOUNDS
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The invention relates to processes for preparing 17-alkynyl-7-hydroxy- steroids, such as 17-Ethynyl-10R13S-dimethyl 2,3,4,7,8R,9S, 10,11,12,13,14S,15,16,17-hexadecahydro-1 H-cyclopenta[a]phenanthrene- 3R,7R,17S-triol (also referred to as 17α-ethynyl-androst-5-ene-3β,7β,17β-triol), that are essentially free of process impurities having binding activity at nuclear estrogen receptors.
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Page/Page column 13; 14
(2009/12/28)
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- C19-Steroids as androgen receptor modulators: Design, discovery, and structure-activity relationship of new steroidal androgen receptor antagonists
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Dehydroepiandrosterone (DHEA), the most abundant steroid in human circulating blood, is metabolized to sex hormones and other C19-steroids. Our previous collaborative study demonstrated that androst-5-ene-3β,17β-diol (Adiol) and androst-4-ene-3,17-dione (Adione), metabolites of DHEA, can activate androgen receptor (AR) target genes. Adiol is maintained at a high concentration in prostate cancer tissue; even after androgen deprivation therapy and its androgen activity is not inhibited by the antiandrogens currently used to treat prostate cancer patients. We have synthesized possible metabolites of DHEA and several synthetic analogues and evaluated their role in androgen receptor transactivation to identify AR modulators. Steroids with low androgenic potential in PC-3 cell lines were evaluated for anti-dihydrotestosterone (DHT) and anti-Adiol activity. We discovered three potent antiandrogens: 3β-acetoxyandrosta-1,5-diene-17-one 17-ethylene ketal (ADEK), androsta-1,4-diene-3,17-dione 17-ethylene ketal (OAK), and 3β-hydroxyandrosta-5,16-diene (HAD) that antagonized the effects of DHT as well as of Adiol on the growth of LNCaP cells and on the expression of prostate-specific antigen (PSA). In vivo tests of these compounds will reveal their potential as potent antiandrogens for the treatment of prostate cancer.
- Marwah, Padma,Marwah, Ashok,Lardy, Henry A.,Miyamoto, Hiroshi,Chang, Chawnshang
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p. 5933 - 5947
(2007/10/03)
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- Microbiological degradation of sterol side chains to a 17-keto group
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The side chains of sterols are degraded by fermentation with microorganisms capable of doing so in an improved manner by employing in such fermentations sterol derivatives of the formula STR1 wherein n is 1 or 2; R1 is H or lower alkyl, R2 is alkyl, whose chain optionally is interrupted by an oxygen atom, or when n is 2, also a hydrogen atom; and R3 is a sterol side chain.
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