synthesis of aryl-substituted γ-lactonesbearing an α-phosphorusylide moiety through the assembly of dimethylacetylenedicarboxylate (DMAD), electron-deficient aldehydes, and triaryl- or trialkylphosphanes in moderate to good yields. The formation of γ-lactones is highly dependent on the reaction time, the phosphane nucleophile, and the molar ratio of DMAD, aldehyde, and phosphane. We found that reactions