Gold-catalyzed cyclization of propargylic diynes: Ethers vs acetates - Related products but different pathways

Diyne substrates bearing one propargylic ether instead of the previously published propargylic acetates were subjected to a gold catalyst. alpha-Naphthol derivatives were obtained as products of the cycloisomerization. The close relationship of the products to the corresponding cyclizations implicated a related mechanistic scenary at first, but further studies favour a mechanistic pathway that is completely different. (C) 2015 Elsevier B.V. All rights reserved.