Stereoselective synthesis of 3-oxo-2-C-branched glycosides from 2,3-unsaturated sugars via [3,3]-sigmatropic rearrangement

Abstract

A number of monosaccharide-derived glycals were initially converted to the corresponding 3-O-allyl 2,3-unsaturated glycosides and then subjected to Claisen rearrangement to produce 3-oxo-2-C-branched sugar derivatives with good to excellent stereoselectivity. The methodology was extended to synthesize allyl vinyl ethers derived from disaccharides. The application of the developed protocol was showcased by synthesizing the bicyclic core unit of the iridoid frameworks.