CHEMICAL SYNTHESIS OF A (12)-D-GLUCOPYRANAN

Article abstract of DOI:10.1016/S0008-6215(00)81872-8

1,2-Anhydro-3,4,6-tri-O-benzyl-α-D-glucopyranose was polymerized with a number of Lewis acids.Phosphorus pentafluoride at -60 deg C caused polymerization to a product rich in β linkages.Other Lewis acids at higher temperatures gave perbenzylated polysaccharides of lower molecular weight with less stereoselectivity.Debenzylation of the most-regular derivative gave a polysaccharide whose specific rotation was +14.7 degree and whose (13)C-n.m.r. spectrum had six absorptions corresponding to those of natural (1<*>2)-β-D-glucopyranans and additional minor peaks presumably due to some α-anomeric configurations.It was estimated to have ca. 90percent of β linkages.