Rh(II) Carbene-Promoted Activation of the Anomeric C−H Bond of Carbohydrates: A Stereospecific Entry toward α- and β-Ketopyranosides

In this communication we report a new strategy toward ketopyranosides based on a carbene-mediated activation of the anomeric C−H bond of carbohydrates. By forming a new carbon−carbon bond after a glycosylation step, this approach enables the preparation of both α- and β-ketopyranosides from advanced precursors.