Synthesis of Allenyl Esters by Horner–Wadsworth–Emmons-Type Reactions of Methyl 2-[Bis(benzylthio)phosphoryl]acetate and Ketenes Using Grignard Reagents

Abstract Methyl 2-[bis(benzylthio)phosphoryl]acetate and its analogues have proven to be efficient Horner–Wadsworth–Emmons (HWE)-type reagents for synthesizing conjugated allenyl esters and their analogues through reactions with disubstituted ketenes using Grignard reagents. A series of HWE-type reagents containing the bis(benzylthio)phosphoryl group showed better reactivity than the corresponding HWE reagents, where two phosphorus–sulfur bonds were substituted with phosphorus–oxygen bonds.