Progress in the Synthesis of 2,3-unsaturated Glycosides

The substitution reaction of glycal (1,2-unsaturated cyclic carbohydrate derivative) at C1 by allyl rearrangement in the presence of a catalyst is called Ferrier type-I rearrangement. 2,3-Unsaturated glycosides are usually obtained from glycals through Ferrier type-I rearrangement, and their potential biological activities have gradually attracted widespread attention of researchers. This review summarizes recent advances (2009- present) in the application of various types of catalysts to Ferrier type-I rearrangement reactions, including their synthesis, mechanism, and application of 2, 3-unsaturated glycosides.