Platinum- and Gold-Catalyzed Hydrative Carbocyclization of Oxo Diynes for One-Pot Synthesis of Benzopyrones and Bicyclic Spiro Ketones

We report a one-pot synthesis of benzopyrones and tricyclic spiroketones from hydrative carbocyclization of oxodiyne substrates catalyzed by PtCl2 and PPh3AuCl/AgOTf, respectively. The distinct carbocyclizations with Pt and Au catalysts stem from their altered regioselectivity in the oxo-assisted hydration of the neighboring alkyne carbons.