1,2-cis-glycosylations : method development and synthesis of complex oligosaccharides

摘要

The glycosylation, the reaction which forms a bond between sugar molecules (the donor and the acceptor), is the central reaction in carbohydrate chemistry. Despite tremendous advances in the past decades, however, the glycosylation reaction remains relatively poorly understood. Especially the formation of 1,2-cis glycosidic linkages remains a significant challenge.This thesis describes an investigation of the influence of reactivity and selectivity of several classes of carbohydrate donors and –acceptors on the selectivity in glycosylation reactions. Special emphasis was placed on the influence of protecting groups on the donor, and nucleophilicity of the acceptor, two major factors that play a tremendous role in the outcome of a glycosylation reaction.The obtained knowledge has been applied in the synthesis of complex carbohydrate molecules, native to pathogens such as Staphylococcus aureus, of which antibiotic-resistant forms such as MRSA present significant danger in hospitals, and the parasite Schistosoma mansoni, causative agent of the neglected tropical disease schistosomiasis. The synthesis of these molecules can play a part in the development of vaccines targeted against these pathogens.