Stereoselective Construction of Polyether trans-Pyran Ring System by Gold(I)-Catalyzed Cyclization

Many natural polyether toxins contain the trans -pyran ladder structure. We describe a synthesis of the polyether trans -pyran ring system by using cationic gold(I)-catalyzed cyclization. This gold(I)-catalyzed cyclization provided high diastereoselectivity and high turnover. This method is expected to be applicable to the synthesis of polyethers.