Stereochemical control in the synthesis of tetrahydrofurans by cyclisation of diols with [1,2]-phenylsulfanyl migration

摘要

Acid catalysed rearangement of a series of 4-PhS-1,3-diols with toluene-p-sulfonic acid in benzene gives stereospcifically substituted 3-PhS-tetrahydrofurans in excellent yield via a[1,2]-SPh shift. We comment on the structural variation at both the migration origin and terminus n the outcome of the title reaction and define its limits.