Synthesis of tetrahydrobenzo[b]furans via a gold(I)-catalyzed rearrangement/cycloisomerization sequence of cyclic 1-aryl-2-propargyl-cyclohex-2enols

A facile synthesis of tetrahydrobenzo[b]furans via gold(I)-catalyzed cycloisomerization of 1-aryl-2-propargylcyclohex-2-enols is described. The transformation is suggested to proceed through a gold(I)-catalyzed tertiary allylic alcohol rearrangement to give a secondary allylic alcohol that underwent a 5-exo-dig addition of the hydroxyl group onto the gold(I)-activated alkyne to give a vinylgold species. Protodeauration of the resulting vinylgold intermediate followed by aromatization furnished the tetrahydrobenzo[b]furans.