BF3·OEt2 Enhanced Yb(OTf)3-Promoted Glycosidation of 1-O-Acyl-D-Glucopyranose

Much attention has been paid to the synthesis of glycosides and oligosaccharides for the preparation of natural products and their analogues to investigate biological functions. 2 Most known glycosidation methods are based on the activation of a leaving group at the anorneric center of a glycosyl donor. 3 In some cases alcohol derivatives such as ROSnBu3 and ROSiMe3 are used to increase the reactivity of glycosyl acceptors. 3 1. Dedicated to the memory of Professor Akira Hasegawa.