Authors: Xing Dai, Huw M. L. Davies
Ad. Syn. Cat.,
2006, 348, 16-17, 2449-2456
The tandem Diels–Alder reaction/ring expansion between cyclopentadiene and unsaturated aldehydes is a highly stereoselective process for the synthesis of bicyclo[3.2.1]octenones, the formal products of a [4+3] cycloaddition. When the initial cycloaddition was conducted in the presence of the chiral Lewis acid catalyst 14, the bicyclo[3.2.1]octenones were obtained in two steps in 72–85 % yields with up to 96 % ee and>98 % de.