A New Way toward Z α,β Unsaturated Esters: A Pyrethroid Application

Article abstract of DOI:10.1021/jo00028a034

Use of the stereospecific condensation of β carbalkoxysulfones with aldehydes, followed by the stereospecific reduction of the afforded sulfonyl acrylate with sodium dithionite allows us to propose this method as a new way to prepare Z α,β unsaturated esters.Steric hindrance seems to be the reason for the selectivity of the reduction and the mechanism was proved, by X-ray of an intermediate, to be a cis Michael addition of HSO2^-, followed by an anti elimination of SO2 and the sulfinate group.This method discovered in the pyrethroid series for the synthesis of acrinathrin 1 could have general application.