Installation of electron-donating protective groups, a strategy for glycosylating unreactive thioglycosyl acceptors using the preactivation-based glycosylation method.

ABSTRACT: Preactivation-based chemoselective glycosylation is a powerful strategy for oligosaccharide synthesis with its successful application in assemblies of many complex oligosaccharides. However, difficulties were encountered in reactions where glycosyl donors bearing multiple electron-withdrawing groups failed to glycosylate hindered unreactive acceptors. In order to overcome this problem, it was discovered that the introduction of electron-donating protective groups onto the glycosyl donors can considerably enhance their glycosylating power, leading to productive glycosylations even with unreactive acceptors. This observation is quite general and can be extended to a wide range of glycosylation reactions, including one-pot syntheses of chondroitin and heparin trisaccharides. The structures of

SUBMITTER: Zeng Y 

PROVIDER: S-EPMC2661424 | biostudies-literature | 2008 Oct

REPOSITORIES: biostudies-literature