Synthesis and 13C NMR spectra of disaccharides related to glucoxylans and xyloglucans

Abstract

β-(1 → 2), (1 → 3) and (1 → 4) linked D-glucopyranosyl-D-xylopyranoses were obtained in high yields via condensation of 2,3,4,6-tetra-O-acetyl-α-D-glucopyranosyl bromide with the appropriate benzyl di-O-benzyl-β-D-xylopyranosides under conditions of modified Koenigs-Knorr reaction and deprotection of the acetyl and benzyl groups. 4-O-β-D-Xylopyranosyl-D-glucopyranose was synthesized similarly starting from 2,3,4-tri-O-acetyl-α-D-xylopyranosyl bromide and 1,2,3,6-tetra-O-acetyl-β-D-glucopyranose; it served as a xyloglucan model substance. The 13C NMR spectra of final disaccharides and their intermediates are presented.