David Cato, T. Buskas, G. Boons
Aug 1, 2005
Citations
0
Influential Citations
33
Citations
Journal
Journal of Carbohydrate Chemistry
Abstract
The activation of 2‐azido‐2‐deoxy Tn and TF thioglycosyl donors by the powerful thiophilic promoter system Ph2SO/Tf2O has been investigated. Glycosylation of an Fmoc‐protected threonine derivative gave 1,2‐cis glycosides in high yields and excellent stereoselectivities. The galactosylation of phenyl 2‐azido‐4,6‐O‐benzylidene‐2‐deoxy‐1‐thio‐β‐D‐galactopyranoside was achieved in high yield and without orthoester formation using a trichloroacetimidate donor carrying a 2‐O‐(2,5‐difluorobenzoyl) group. The anomeric thiophenyl group of the constructed TF disaccharide could directly be activated by the van Boom promotor for the glycosylation of a threonine derivative. * Dedicated to the memory of Professor Jacques H. van Boom