Process for preparing the 17 - methyl - 20 - alkyl - 18 - norpregnènes

摘要

Novel steroids of the formula FORM:1055078/C2/1 wherein the A and B rings have one of the structures FORM:1055078/C2/2 (wherein R is C1-4 alkyl and R1 and R11 ar each either hydrogen or acetyl) are prepared by reacting steroids of the formula FORM:1055078/C2/3 (wherein the A and B rings have one of the 3-hydroxy or -acyloxy-containing structures depicted above) with an alkyl Grignard reagent at a temperature between - 10 DEG and + 30 DEG C. in an inert, anhydrous, organic solvent with subsequent mild hydrolysis in water, to give a steroid of the first general formula above wherein R11 is hydrogen and the A and B rings are as in the starting material. Then subsequently 3b -acetates are hydrolysed to 3b -ols, the 3b ,16a -diols are acetylated to the diacetates (which can also be obtained by acetylation of the 3-mono-acetates) and these may be hydrolysed to give the 3b ,16a -diols again. The D 5-3-ols or their acylates may be catalytically hydrogenated to the 5,6-saturated compounds. The D 4-3-ones are prepared by oxidation of the D 5-3-ols, and on catalytic hydrogenation they yield the ring A saturated 3-ones. The 16-monoacetoxy compounds are prepared by standard methods from the 3-oxo-16-ols.