14-Methyl steroids. Part 4. Synthesis of 14β-methylestradiol and related 14β-methyl-19-norsteroids

Abstract

3-Methoxy-14-methyl-14β-estra-1,3,5(10), 16-tetraen-15-one (2) has been converted via the derived 16β,17β-epoxy 15-ketone (3) into 14-methyl-14β-estra-1,3,5(10)-triene-3,17β-diol (27) and the corresponding 3,17α-diol (28). The overall course of the reduction of compound (3) with lithium aluminium hydride has been elucidated with the aid of the fully assigned 500 MHz ¹H n.m.r. spectra of the reduction products and their selectively deuteriated analogues. Reduction of the epoxy alcohol (14) to the diol (15) with lithium aluminium hydride takes place via an unusual epoxide rearrangement.