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[摘要]：2-O-Propargyl-substituted glycosyl donors and O-(2-azidobenzyl)-substituted acceptors having a vicinal hydroxy group readily underwent the click reaction. Intramolecular glycosidation with N-iodosuccinimide/trifluoromethansulfonic acid as the activating system afforded beta-(1-3)-and alpha-(1-2)-linked disaccharides as part of 14-membered macrocycles. Descriptors for these reactions are proposed that consider the donor and acceptor attachment sites and the stereochemistry of the functional groups. Investigation of the influence of 2-O-linked 1-aryl-1,2,3-triazol-4-ylmethyl groups, as contained in the spacer, on the anomeric selectivity exhibited no anchimeric assistance. In addition, it was shown that the spacer group can be readily cleaved under Birch reduction conditions. |
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