Synthesis of the mannopeptimycin disaccharide and its conjugation with 4-alkylidene-β-lactams

The disaccharide moiety of the antibiotic mannopeptimycin has been synthesized as a (N-phenyl)trifluoroacetimidate donor, the reactivity of which was tested in conjugation with a 4-alkylidene-beta-lactam acceptor. Key steps of the synthesis were Bi(OTf)(3)-catalyzed glycosidations that proceeded in short times and with high yields and stereocontrol. ((c) Wiley-VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2008).