Stereoselective synthesis of a novel Galf-disaccharide mimic: β-d-galactofuranosyl-(1-5)-β-d-galactofuranosyl motif of mycobacterial cell walls

A Galf-disaccharide mimic, an analogue of the acceptor substrates of mycobacterial Galf-transferases, was obtained by nucleophilic addition of a l-arabinofurano-alkyne to iminogalactitol-derived nitrone. Remarkably, the nucleophilic addition could be performed highly efficiently and stereoselectively in the presence of diethylzinc in toluene using protected nitrone and alkynyl sugar as reaction partners and thus opens a concise approach to a diversity of disaccharide mimics.