Synthesis of Protected N‐Acetylchitooligosaccharide and Its Analogues: A Versatile Approach for the Synthesis of Complex Oligosaccharides of 2‐Amino‐2‐deoxy Sugar

Abstract

AbstractA stepwise synthesis of oligosaccharide chains containing 2‐amino‐2‐deoxy‐D‐glucopyranose units was elaborated as a new versatile approach for preparation of biologically important oligosaccharides having 2‐amino‐ 2‐deoxysugars. Utilizing N‐phthalic acyl group as the protective group of amine, and phenylthiolate as the leaving group at the reducing terminal, protected N‐acetylchitooligosaccharide and its analogues, methyl (3‐O‐acetyl‐4,6‐O‐ benzylene‐2‐deoxy‐2‐phthalimido‐β‐D‐glucopyranosyl)‐(1→4)‐3‐O‐acetyl‐6‐O‐benzyl‐2‐deoxy‐2‐phthalimido‐β‐D‐glucopyranoside 4, methyl (3‐O‐acetyl‐4,6‐O‐benzylene‐2‐deoxy‐2‐phthalimido‐β‐D‐gluco‐pyranosyl)‐(1→4)‐ (3‐O‐acetyl‐6‐O‐benzyl‐2‐deoxy‐2‐phthalimido‐β‐D‐glucopyranosyl)‐(1→4)‐3‐O‐acetyl‐6‐O‐benzyl‐2‐deoxy‐2‐phthalimido‐β‐D‐glucopyranoside 6, methyl (3‐O‐acetyl‐4,6‐O‐benzylene‐2‐deoxy‐2‐phthalimido‐β‐D‐glucopyranosyl)‐(1→3)‐4,6‐O‐benzylene‐2‐deoxy‐2‐phthalimido‐β‐D‐glucopyranoside 8, and methyl (3‐O‐acetyl‐4,6‐O‐benzylene‐2‐deoxy‐2‐phthalimido‐β‐D‐glucopyranosyl)‐(1→3)‐(4,6‐O‐benzylene‐2‐deoxy‐2‐phthalimido‐β‐D‐glucopyranosyl)‐(1→3)‐4,6‐O‐benzylene‐2‐deoxy‐2‐phthalimido‐β‐D‐glucopyranoside 10, were designed and synthesized by amino glucose as the starting material, which were all characterized by 1H NMR, 13C NMR and HRMS.