Gold-Catalysed Activation of Epoxides: Application in the Synthesis of Bicyclic Ketals

Gold-catalysed generation of diol equivalents from epoxides and their intramolecular reaction with C C bonds to generate bicyclic ketals is presented. This reaction essentially involves the formation of an acetonide, which subsequently cyclises on the alkyne intramolecularly under gold catalysis conditions. This method could be extended to make optically pure bicyclic ketals. Deuterium incorporation experiments were carried out to ascertain the mechanism of the reaction.