SUPERARMED GLYCOSYL DONORS IN CHEMICAL GLYCOSYLATION

Only recently has the tremendous biological significance and therapeutic potential of carbohydrates and conjugates thereof (glycoproteins, glycolipids, proteoglycans, etc.) begun to emerge. As the appreciation for the biological roles of carbohydrates a growing demand for efficient and scalable methods towards the synthesis of these challenging molecules has become even more imperative. This has led to the development of a variety of expeditious strategies for oligosaccharide assembly. Amongst these strategies, the so-called armed-disarmed strategy introduced by Fraser-Reid is of particular attractiveness as it allows for chemoselective oligosaccharide synthesis. Recently, the conformational changes as well as the strategic placement of common protecting groups have led to the discovery of new methods for “superarming” of glycosyl donors. This doctoral dissertation is dedicated to the exploration of new methods and strategies for efficient oligosaccharide assembly. The main focus of this work is centered on the detailed study of the superarmed glycosyl donors and broadening their application to the chemoselective oligosaccharide assembly. This study was supplemented by the discovery of new leaving groups and application to the synthesis of biologically important oligosaccharides containing residues of sialic acid