Unsaturated steroids. Part 8. Synthesis of ergosta-5,7-diene-1α,3β-diol, the 4,4-dimethyl analogue, and 4,4-dimethylergosta-5,7-dien-3β-ol

Abstract

From 5α-ergost-7-en-3-one, by employing the method used² for the preparation of the cholestane analogue, ergosta-5,7-diene-1α,3β-diol (1; R = Me) has been synthesised. Methylation of ergosta-1,4,7-trien-3-one (2) gave 4,4-dimethylergosta-1,5,7-trien-3-one. The corresponding 1α,2α-epoxide (3), furnished 4,4-dimethylergosta-5,7-diene-1α,3α-diol (4; R =α-OH) and the corresponding 1α,3β-diol (4; R =β-OH). 4,4-Dimethylergosta-5,7-dien-3β-ol has been obtained from 22,23-dihydroergosterol by standard methods.