Mechanism of the [1,3] phenylthio shift in the rearrangement of allyl sulphides

Abstract

Substituted allyl phenyl sulphides undergo a [1,3] allylic phenylthio shift by thermal, light-induced, and in some cases acid-catalysed pathways. Conditions are defined for causing or preventing the [1,3] shift and some of the factors which establish the position of equilibrium are identified. Crossover experiments suggest that the thermal and photochemical reactions occur by a radical chain mechanism and the acid-catalysed reaction via an allyl cation.