Studies on carbohydrates. Part 33: Synthesis of spacer-armed 2-acetamido-2-deoxy-4-O-β-d-galactopyranosyl-α-d-mannosides and their dimers

Abstract The mixture of 3,6-di- O -acetyl-4- O -(2,3,4,6-tetra- O -acetyl-β- d -galactopyranosyl)-2-azido-2-deoxy- d -glucopyranosyl 1-acetates or 1-trichloroacetates and the corresponding mannose type glycosyl donors reacted with the spacer arms di- and triethylene glycol, in dichloromethane solution with BF 3 ·OEt 2 and TMSOTf as promotors at room temperature to give highly selective products. Only the mannose type products were obtained.