Abstract A simple and convenient synthetic approach to dihydrofurans has been developed from the cyclization of 2-propynyl-1, 3-dicarbonyl compounds catalyzed by potassium tert- butoxide, copper (II) trifluoromethanesulfonate and triphenylphosphine using methanol/ dichloromethane as the solvent under very mild conditions. Moreover, dihydrofurans could be easily transformed into the corresponding furans in the presence of trifluoroacetic acid.
