ABSTRACT
In this chapter, the authors describe the synthesis of linear and hyperbranched stereoregular aminopolysaccharides by the oxazoline glycosylation method of sugar oxazoline monomers having hydroxy groups. Glycosylation, a reaction for the synthesis of glycosides, usually involves the condensation of a protected glycose derivative with an appropriate aglycon derivative. The oxazoline method is one of the excellent glycosylations for high stereoselectivity, in which the stereospecific glycosylation of alcohol with an oxazoline of an amino sugar was achieved in the presence of an acid catalyst to give β-glycoside. Acid-catalyzed polymerization of sugar oxazoline monomers 1 and 4 proceeded by stereoregular glycosylation to give natural- and non-natural-type aminopolysaccharides 2 and 5, respectively. Synthesis of aminopolysaccharides, therefore, is one of the important research areas in the field of functional materials, examples of biorelated polymers, antibacterial substance, and biodegradable polymers as well as materials for drugs and matrices of drug delivery systems.
