A Convenient Synthesis of 5-Oxo-5,6,7,8-tetrahydro-4H-benzo-[b]-pyran Derivatives Catalyzed by KF-Alumina

Abstract
A series of 5-oxo-5,6,7,8-tetrahydro-4H-benzo-[b]-pyran derivatives were prepared by the reaction of arylmethylidenemalononitriles or 2-cyano-3-aryl-l-acrylate with 5,5-dimethyl-1,3-cyclohexanedione (dimedone) in DMF at room temperature catalyzed by KF-alumina. The structure of the product was confirmed by X-ray analysis.