Contiguous Quaternary Centers from a AuI‐Catalyzed Nazarov Cyclization

Abstract

The cationic AuI‐catalyzed cyclization of highly substituted enynes has been shown to provide cyclopentenones with up to two contiguous, all‐carbon atom quaternary centers in a diastereospecific process. In the more challenging examples in which two contiguous quaternary centers are formed during cyclization, the essential role of a ethoxycarbonyl group to control the reaction outcome has been demonstrated. The less challenging examples that lead to a single quaternary center in the ring require no activation by aryl or by electron withdrawing groups.