Diastereoselective asymmetric cyclopropanation of (S)-(+)-α-(diethoxyphosphoryl)vinyl p-tolyl sulfoxide

Abstract

The title sulfoxide 1 reacts with fully deuterated dimethylsulfoxonium methylide, diphenylsulfonium isopropylide and diphenyldiazomethane to form the corresponding cyclopropanes 4 as single diastereoisomers; the chirality of the cyclopropane (+)-4c obtained from 1 and diphenyldiazomethane is (S_S,S_C) as determined by X-ray diffraction analysis; based on experimental data, the steric course of the asymmetric cyclopropanation is proposed.