New approaches to glycoconjugate synthesis

Abstract

Generally convergent strategies are employed in glyconjugate synthesis, hence the oligosaccharide moiety and the aglycon moiety are separately prepared and then linked to yield the target molecule; for glycopeptides linear synthesis strategies are more successful. - The importance of β-glycosidic linkages of glucosamine and galactosamine in glycoconjugates was reason for the development of new methods which are based on N,N-diacetyl, N-tetrachlorophthaloyl, and N-trichloroethoxycarbonyl protection. - Another important goal in the construction of oligosaccharides is solid phase synthesis; the application of O-glycosyl trichloroacetimidates as donors, thiolinkers to the solid phase, and MALDI-MS for product analysis led to improvements in this regard. - Trichloroacetimidate-based glycosylation can be also applied to the synthesis of acid labile glycosyl phosphates and their lipid and nucleoside derivatives. Hydrolytically more stable glycophospholipids are GPI anchors; a general approach for ceramide-1-phosphate and phosphatidic acid derived GPI anchors is based on a versatile building block strategy.