[1,4] Phenylthio migrations in the rearrangement of 2,4,4-tris(phenylthio)butanols

Abstract

2,4,4-Tris(phenylthio)butanols rearranged by a [1,4]-PhS shift to give an E,Z mixture of vinyl sulfides with thionyl chloride but only the Z isomer with toluene-p-sulfonic acid. The [1,4]-PhS shift occurred only if another PhS group was present β to the hydroxyl group. The mechanism and scope of the reaction and the preparation of 2,4,4-tris(phenylthio)butanols via Michael addition of dithioacetal nucleophiles to methyl crotonate followed by α-sulfenylation is reported.