On orthogonal and selective activation of glycosyl thioimidates and thioglycosides: application to oligosaccharide assembly.

ABSTRACT: Discrimination among S-thiazolinyl (STaz), S-benzoxazolyl (SBox), and S-ethyl anomeric leaving groups was achieved by fine-tuning activation conditions. Preferential glycosidation of a certain leaving group is determined neither by the strength of the activating reagent nor by the stability of the leaving group itself; instead, the type of activation plays the key role. The activation conditions established herein were applied to a sequential five-step synthesis of a hexasaccharide using six monosaccharide building blocks equipped with six different leaving groups.

SUBMITTER: Kaeothip S 

PROVIDER: S-EPMC3170487 | biostudies-literature | 2011 Sep

REPOSITORIES: biostudies-literature