Unusual participation of O-propargyl group during the cyclization of 6-hydroxy-2-propargyl ethers of aryl chalcones: one-pot synthesis of 2-acyl-3-styrylbenzofuran and 7-aryldibenzo[b,d]furan-1,7-diols

An unusual participation of the O-propargyl alkyne group during the cyclization of 6-hydroxy-2-propargyl ethers of aryl chalcones afforded highly functionalized 2-acyl-3-styrylbenzofuran and 8-aryl dibenzo[b,d]furan-1,7-diol derivatives. A plausible mechanism and scope of the reaction is provided.