Regioselective Bismuth-Catalyzed Synthesis of Pyranocoumarins and Furocoumarins from 4-Hydroxycoumarins and Propargyl Alcohols

摘要

An efficient method for the bismuth-catalyzed regioselective synthesis of pyranocoumarins and furocoumarins has been developed from the reaction of 4-hydroxycoumarins with propargyl alcohols. The reaction proceeds through sequential propargylation and intramolecular cyclization reactions catalyzed by bismuth(III) triflate.