Synthesis of Novel 4α-Substituted Sterols

Article abstract of DOI:10.1021/jo00267a018

A series of novel 4α-substituted sterols (9, 10, 11, 14, 15, and 19) has been synthesized as potential inhibitors of sterol 4-demethylation.The key intermediate was 4α-carbomethoxy-5α-cholestan-3-one (1), which was synthesized by regiocontrolled alkylation with methyl cyanoformate.Epoxidation of 4α-vinyl-5α-cholestan-3β-ol (9) gave the diastereoisomeric epoxides (20 and 21) whose stereochemistry was deduced from NMR analysis and deuterium labeling.