Regiospecific synthesis of 2-halo-3-(2'-glucalyl)benzo[b]thiophenes.

Abstract

A regiospecific synthetic strategy for the synthesis of 2-chloro-3-substituted benzo[b]thiophenes is developed via a dichlorocarbene insertion and sigmatropic rearrangement of an in situ generated ylide. The current protocol provides a reversed regiochemistry to the commonly employed electrophilic cyclization reaction for the synthesis of benzo[b]thiophenes and access to their hitherto under-represented chlorinated derivatives.