摘要:
Orthoester-linked D-arabinofuranose oligosaccharides were isolated in high yield for the first time via glycosylations with 2-O-chloroacetyl-substituded D-arabinofuranose thioglycosides promoted by NIS-AgOTf in the presence of 4 A molecular sieves in CH2Cl2. These orthoesters can be rearranged into the isomeric glycosidically-linked oligosaccharides by treatment with TMSOTf in CH2Cl2, or in situ by extension of the reaction time. (C) 2011 Elsevier Ltd. All rights reserved.