Ring-contraction of 5β,6β-epoxyandrostane-4,17-dione
Abstract
Stereospecific methods for the preparation of 5α,6α- and 5β,6β-epoxyandrostane-4,17-dione are described. A Favorskii-type ring contraction of the 5β,6β-epoxide affords a rapid route to A-nor-steroids.