Stereoselective synthesis of C-2-methylene and C-2-methyl-C-glycosides by Claisen rearrangement of 2-vinyloxymethyl glycals

Abstract

An efficient protocol for the stereoselective synthesis of C-2-methylene-α- and -β-C-glycosides by a Claisen rearrangement of 2-vinyloxymethyl glycal derivatives is reported. A plausible mechanism for the formation of α-selective-C-glycoside was proposed. The methodology was further extended to the high diastereoselective synthesis of C-2-methyl-C-glycosides.