Copper‐Catalyzed (3+2) Annulation of 5‐Ethynyloxazolidine‐2,4‐diones with Benzoylacetonitriles: Synthesis of Dihydrofuran Derivatives

Abstract The copper‐catalyzed (3+2) annulation of 5‐ethynyloxazolidine‐2,4‐diones with acylacetonitriles worked well under mild reaction conditions to afford biologically important 2,3‐dihydrofuran derivatives having an amide moiety in moderate to high yields. A wide scope of easily accessible 5‐ethynyloxazolidine‐2,4‐diones and acylacetonitriles were tolerated. The successful scale‐up reaction demonstrated that the reaction is a useful method for the synthesis of 2,3‐dihydrofuran derivatives.