Gold(I)-Catalyzed Enyne Cyclizations: Studies Toward the Total Synthesis of (+)-Aureol

Abstract

We report a modular synthetic approach toward the total synthesis of (+)-aureol based on a bioinspired gold(I)-catalyzed enyne cascade cyclization reaction. First, we investigated an array of catalysts to promote a 6-<i>endo</i>-dig cyclization of a highly advanced enediyne precursor. Since these studies result exclusively in the formation of the 5-<i>exo</i>-dig product, we synthesized and investigated a dienyne cyclization precursor in order to form the benzo[<i>d</i>]xanthene skeleton in a stepwise fashion.