Reaction of Dichloroketene with Cyclic Thioketals of α,β-Cycloalkenones: Synthesis of 1,7-Dithiacycloalk-5-en-2-one Derivatives by a Four-Carbon Cycloenlargement

Article abstract of DOI:10.1021/jo00324a007

Cyclic thioketals of α,β-cycloalkenones undergo a four-carbon cycloenlargement of the 1,3-dithia n-membered ring by reaction with dichloroketene to give 1,7-dithiacycloalk-5-en-2-one derivatives in good yields at room temperature.A mechanistic pathway for the regioselective inclusion of the dichloroketene moiety in a formally <4 + 2> cycloaddition process is proposed.This reaction of dichloroketene is remarkable for its simplicity and appears useful for synthesis of multifunctional dithia macrocyclic systems.