Indium-Mediated Preparation of Bis(α-hydroxyallenes) or α,α′-Dihydroxyallenynes and Further Gold-Catalyzed Cyclizations

Abstract

We present the regio-and diastereoselective Barbier-type allenylation reaction of glyoxals mediated by indium to furnish highly valuable syn-bis(α-hydroxyallenes) and syn-α,α′dihydroxyallenynes. The gold-catalyzed controlled cyclization of these unsaturated diols enables the divergent preparation of three types of oxacycles.