ABSTRACT
Thioglycosides are important building blocks in the synthesis of oligosaccharides and glycoconjugates.1 Besides being used as glycosyl donors, they can be exploited as precursors for other donor types. To this end, the anomeric thio-functionality acts as a temporary masking group for the anomeric hydroxyl group, to be used in glycosylation reactions featuring dehydrative coupling conditions2 or as an intermediate for trichloroacetimidate1a,b and triuoro-(N-phenyl)acetimidate3 donor synthesis. Many conditions for the hydrolysis of anomeric thio-functionalities have been reported. Examples of anomeric thio-hydrolyzing systems include N-iodosaccharin in wet acetonitrile,4 N-bromosuccinimide (NBS) in wet acetone,5 and N-iodosuccinimide (NIS) and triuoroacetic acid (NIS/TFA) in wet dichloromethane (DCM).6
