3a-Hydroxy-5/3-pregnan-20-one

Hydroxy-6-methyl-10 (5 6) abeo-cholestan-5-one acetate, 391 3 a-Hydroxy-16a-methyl-11,20-dioxo-5/3-pregnane-21-glyoxylic acid, 191 17 -Hydroxy-l-niethyl-A-homo-5a-androst-l-en-3-one acetate, 362 17 /3-Hy droxy-5a, 1 Oa-methy lene-A-norestran-3-one, 429 17 3-Hydroxy-17 a-methyl-10 ( 5 4) -fl( < o-estrane-3,5-dione, 314 3a-Hydroxy-16a-methyl-5/3-pregnane-11,20-dione, lyl... 

Esters of hydroxy ketones are prepared by acetoxylation with lead tetraacetate in benzene. Cyclohexanone furnishes a 75% yield of 2-ace-toxycyclohexanone and a 3% yield of cis-2,6-diacetoxycyclohexanone after heating at 80 C for 8 h [438], Similarly, 3a-hydroxy-5p-pregnan-20-one yields 64% of 21-acetoxy-3a-hydroxy-5 -pregnan-20-one [439] after 4 h at room temperature. 

A series of pregnane-17-thiol derivatives (e.g. 16a-OH-17a-SH, 16/8-OH-17a-SH, and 16/8-OH-17/8-SH derivatives of progesterone, and some of their esters) has been prepared for biological evaluation. 3a,6a-Dihydroxy-5a-pregn-9(ll) en-20-one, isolated from starfish, has been synthesized from 1 la-hydroxy-progesterone. 5-Bromo-6/8 -fluoro-3/8,16a, 17a -trihydroxy-5a -pregnan-20-one... 

The 3/3-azido-A -steroids are obtained on treatment of the 3/5-tosyloxy-A -steroids, or better the 3a,5a-cyclo-6-hydroxy-steroids, with a solution of hydrazoic acid in benzene in the presence of an excess of BFg. Reduction of the azide function is effected with LiAlH4 (Scheme 2). Holaphyllamine (39) has been prepared from 3a,6a-ditosyloxy-5/5-pregnan-20-one (37), by way of the azide (38). The introduction of a 20a-amino-group in a steroid can be effected starting from the corresponding acid and making use of the stereospecificity of the... 

Five 20-oxosteioids (pregnenolone, 3 -hydroxy-5a-, 3) -hydrpxy-5) -, 3a-hydropy-5a- and 3-hydroxy-5) -pregnan-20-one) and their sulfates were separated as their 4- A, Ar -dimethylaminosulfonyl)-7-hydrazino-2,l,3-benzoxadiazole derivatives on a Cjg column (A = 450nm, ex 550nm, em). The mobile phase was a 3/1 methanol/water (4mM y-cyclodextrin). Good resolution was obtained and elution was complete in 25 min [422],... 

The anaesthetic steroid 3a-hydroxy-5a-pregnane-ll,20-dione has normal conformational features, both in the crystal and in solution. X-Ray data show that deoxycholic acid can form an inclusion complex in which alternate molecules of dimethyl sulphoxide and water are held in canals formed by helically arranged host molecules.Six different crystalline forms of 17a-ethynyloestradiol have been recognized. X-Ray structural data are reported for 3-methoxy-2-aza-oestra-l,3,5(10)-trien-17/3-yl acetate, 3/3-hydroxypregn-5-en-20-one (pregnenolone), 5a-cholest-2-ene, 3/3-bromo- and 3/3-chloro-cholest-5-enes, and cholesteryl acetate (at 123 K), benzoate, chloroformate, ° laurate, methyl carbonate, and 24-norcholesteryl acetate. ... 

Nitrous acid deamination of 3a,20)3-diacetoxy-12a-amino-5/5-pregnan-ll-one afforded some c-nor-o-homo-steroid, but the main products were 12 -methyl-l 1-ketones produced by 13-methyl migration which, on treatment with base, underwent retroaldol reaction to give 3a-hydroxy-12-methyl-18-nor-5) -androst-12-en-1 l-one. ° Similar deamination of the 9a-amino-ll-ketone (500) also resulted in methyl migration to a mixture of the 1(10)- and 5(10)-olefins (502) and 10a-hydroxy-compound (501). Epoxidation of the two olefins and subsequent treatment with acid gave 20j5-hydroxy-9 -methyl-19-norpregna-l,3,5(10)-trien-ll-one. 

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