derivatives were obtained in good yields by the reactions of carbonyl compounds with α-phenylthioalkylidenetriphenylphosphorane. Phosphorane was prepared by the equimolar reaction of alkylidenetriphenylphosphorane and N-phenylthio-N-methylacetamide. It was established that, differing from the case of alkylidenetriphenylphosphorane, di-methyloxosulfonium methylide reacted with N-phenylthiophthalimide and