phenylselenenylation of an α-diethoxyphosphinyl-γ-butyrolactone carbanion and subsequent oxidative elimination of the phenylseleno residue. The butenolide 2 underwent the Michael addition of various nucleophiles to generate the phosphoryl-stabilized carbanions, which reacted with carbonyl compounds to give α,β-difunctionalized γ-butyrolactones, lignans, and a γ-butyrolactohe annelated compound.