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 alpha- and beta-ketopyranosides from advanced precursors.
Carbene-Mediated Functionalization of the Anomeric CH Bond of Carbohydrates: Scope and Limitations
Herein we investigate the scope and limitations of a new synthetic approach towards α‐ and β‐ketopyranosides relying on the functionalization of the anomeric CH bond of carbohydrates by insertion of a metal carbene. A key bromoacetate grafted at the 2‐position is the cornerstone of a stereoselective glycosylation/diazotransfer/quaternarization sequence that makes possible the construction of a quaternary