Gold(I)-catalyzed reactions: substituents-dependent selective formation of bisfurans and 1,3-diketones from 1-alkynyl-2,3-epoxy alcohols

A mild access to bisfurans and 1,3-diketones via gold(I)-catalyzed transformation of 1-alkynyl-2,3-epoxy alcohols 1 has been described. The formation of bisfurans 2 is proposed to proceed through the sequential formation of 2-hydroxymethylfuran, followed by self-condensation in the presence of gold complex. Whereas the formation of 1,3-diketones 3 is resulted from a domino C–C bond cleavage of epoxide system with the assistance of hydroxyl group and subsequent hydrolysis. Substituents on the oxirane have a significant effect on the selective formation of the two kinds of products.