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Abstract
The use of a dummy ligand to control the conformation of the side chain of hexopyranosyl donors is described. The effect of the dummy ligand in the anomeric selectivity is evaluated with respect to the side chain conformation. The results of the glycosylations showed excellent equatorial selectivities in the case of galacto donors. The electron-withdrawing effect of the side chain in tg conformation gives the best selectivity. For gluco donors with side chain with gg conformation preferred equatorial substitution whereas the gt conformation gave no selectivity. Deprotection of glycosides was carried in one single step with Raney-nickel hydrogenolysis.