Synthesis of Uronic Acid Containing Oligosaccharides

Abstract

Uronic acids are monosaccharides in which the terminal carbon is oxidized to a carboxylic acid. They are important components of many oligo- and polysaccharides and glycoconjugates which are indispensable for various life forms. Synthetic carbohydrate chemistry has seen impressive progress and both large and complex oligosaccharides can be constructed by chemical synthesis. The chemical synthesis of oligosaccharides and glycoconjugates containing uronic acids demands careful planning of the oxidation event, considering the balance between glycosylation efficiency of uronic acid building blocks and challenging late stage oxidation reactions. This chapter reviews methods, possibilities and challenges for the synthesis of uronic acid containing oligosaccharides. By the hand of selected examples, it is illustrated how large and complex acidic oligosaccharides can be assembled following different strategies. First the general synthetic strategies available for the assembly of uronic acid containing oligosaccharides are introduced and next several syntheses are presented of biologically relevant, structurally complex oligosaccharides, focusing on important classes of uronic acid containing oligosaccharides: mammalian glycosaminoglycans, bacterial polysaccharides and plant pectins. Synthetic uronic acid containing oligosaccharides and glycoconjugates are crucial for glycobiology and glycoimmunology research.