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.