Unsaturated steroids. Part 5. Synthesis of 4α-methylcholest-8(9)-en-3β-ol

Abstract

4α-Methylcholest-8(9)-en-3β-ol (1) has been synthesised from 5α-cholest-8-en-3-one by way of 2,2-trimethylenedithio-5α-cholest-8-en-3-one (4; R = H) and the corresponding 4α-methyl derivative (4; R = Me). Alternatively 5α-cholesta-8,14-dien-3-one (5; R = H₂) was converted into the 2,2-trimethylenedithio-derivative (8; R = H), which was monomethylated at C-4. Removal from this 4-methyl compound of the dithio-substituent and subsequent hydrogenation of the 14(15)-double bond gave 4α-methylcholest-8(9)-en-3β-(and 3α-) ol.