Synthesis of monomeric methylene-linked 1,2,3-triazole glycoconjugates from allo- and glucofuranoses

Carbohydrate-triazole conjugates proved themselves as valuable enzyme activity-modifying agents. Recent exploration of nontrivial conjugates in which the bonding is formed not at the glycosidic or terminal carbons of the carbohydrates, but at C-3 position showed a potential of this type of structures as the ligands for various glycosidases and galectins. Here, we report synthesis of protected monomeric 3-C-(triazolylmethyl)-substituted gluco- and alloconjugates. Diastereomeric azides are synthesized from common intermediate, 3-deoxy-1,2:5,6-di-O-isopropylidene-3-oxo-alpha-D-allofuranose, and used in Cu-catalyzed azide-alkyne cycloaddition (CuAAC) reactions with commercial alkynes. The yields of the cycloaddition reactions are good to excellent under different catalytic conditions.