The first In(OTf)3-catalyzed conversion of kinetically formed homoallylic alcohols into the thermodynamically preferred regioisomers: Application to the synthesis of 22α-sterols

Abstract

A retro-ene reaction that generates the parent aldehyde and a sigmatropic rearrangement are involved in the In(OTf)3-catalyzed conversion of homoallylic alcohols 1 into the thermodynamically favored regioisomers 2. This method can be used for the stereocontrolled synthesis of linear homoallylic 22α-sterols from their readily accessible branched 22β isomers.