Gold(I)-Catalyzed Stereoselective Cyclization of 1,3-Enyne Aldehydes by 1,3-Acyloxy Migration/Nazarov/Aldol Cascade

Stereoselective synthesis of bicyclo[3.3.0]octenones from chiral 1,3 enyne aldehydes bearing propargylic acetates is described. The method is based on a Au(I)-catalyzed domino sequence with concomitant transfer of chirality involving 1,3-acyloxy migration followed by Nazarov cyclization and an unprecedented aldol addition. The method furnishes densely functionalized bicyclic structures in high yields, up to 97% ee, and good diastereoselectivity.