AgNO3 catalyzed cyclization of propargyl-Meldrum’s acids in aqueous solvent: highly selective synthesis of Z-γ-alkylidene lactones

γ-Alkylidene lactones have attracted considerable attention due to their diverse biological activities and ubiquitous structural units in natural products. Herein, an efficient AgNO3 catalyzed highly regio- and stereo-selective cyclization of propargyl-Meldrum’s acids in aqueous solvent was developed, which provides a practical synthetic strategy for the synthesis of substituted Z-γ-alkylidene butyrolactones under neutral reaction conditions.