Regiospecificity in the Hydroborationof 6-Hydroxyandrost-4-enes.

Abstract

The hydroboration of 6α- and 6β-hydroxyandrost-4-en-17-one is shown to take place predominantly on the face of the alkenetrans to the allylic hydroxy group. The regiochemistry of the reaction is also modified with the formation of some 5β,6α,17β-trihydroxy-5β-androstane from 6α-hydroxyandrost-4-en-17-one. The structure of this tertiary alcohol was established by X-ray crystallography.