A-glycan synthesis

L-Fucosamine was found as a constituent of Pneumococcus Type V capsular polysaccharide and as a constituent of the mucopolysaccharides (glycosamino-glycans) of certain enteric bacteria A new synthesis was devised to make the amino sugar more available. 

Weiler, S. Schmidt, R. R., A versatile strategy for the synthesis of complex type N-glycans Synthesis of diantennary and bisected dianteimary ohgosaccharides. 

We had for some time considered that aziridines, because of their increased basicity and hence reactivity at the active site of a glycan hydrolase, would prove to be better inhibitors than the epoxides in many respects. Conversely, the less basic thiirans would be expected to be poorer inhibitors than the corresponding epoxides. We thus embarked on a synthesis of the aziridine 30 and the thiiran 31. 

A second method that has been invaluable for accessing glycans is chemical synthesis (see cross references Glycan synthesis, key reaction of Glycan synthesis, key strategies for Glycan synthesis, protection and deprotection steps of and... 

Sohd-phase strategies for glycan synthesis can be broken down into three types donor bonnd, acceptor bonnd, and bidirectional (Fig. 4). In the donor bonnd mode, an excess acceptor is nsed to drive the reaction to completion (or to maximize yields). As the donor in a typical glycosylation reaction is the reactive intermediate, nnprodnctive side reactions correspond... 

Wu, X, Grathwohl, M, Schmidt, R R, Efficient solid-phase synthesis of a complex, branched A-glycan hexasaccharide use of a novel linker and temporary-protecting-group pattern, Angew. Chem. Int Ed, 41, 4489-4493, 2002. 

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