Stereoselective Access to β-C-Glycosamines by Nitro-Michael Addition of Organolithium Reagents

International audienceThe nitro-Michael addition of organolithium species to 2 nitroglycal derivatives was investigated. This methodology affords straightforward and stereoselective access to C-nitroglycosides, which are excellent precursors to C–N-acetyl-glycosamines. The corresponding products bearing an aromatic, heteroaromatic, alkynyl, alkenyl, or alkyl moiety were isolated in good yields with excellent selectivities. The β isomer was isolated as a single stereoisomer in most cases, and the structure was clearly elucidated by NMR spectroscopy experiments