Au-Catalyzed Pentannulation Reaction of Propargylic Esters Occurring at C(sp(3))-H Site.

A gold-catalyzed cascade cyclization reaction of easily accessible propargylic esters to cyclopentenones has been developed. This transformation features an unprecedented pentannulation reaction of propargylic esters which occurs at an unactivated C(sp(3))-H site to efficiently produce functionalized mono-, bis-, and tricyclic cyclopentenones.