New stereospecific routes to both epimers of 2-methyl-3-oxo- and 3-methyl-2-oxo-steroids via 2-lithio-1,3-dithian–epoxide reactions
Abstract
The potential of 2-lithio-1,3-dithian–epoxide reactions for the stereospecific substitution of the steroid skeleton in a desired position has been illustrated by their application in the preparation of both epimers of 2-methyl-3-oxo- and 3-methyl-2-oxo-5α-cholestane.