A New Synthesis of α-Phenylseleno Esters and Acids from Terminal Alkynes

Alkynyl phenyl selenides, easily prepared from terminal alkynes, react with p-toluenesulfonic acid to afford (Z)-α-(phenylseleno)vinyl p-toluenesulfonates. The reactions of these compounds with phenylselenyl sulfate in the presence of alcohols or water give the corresponding α-phenylseleno esters or acids, respectively.