Synthesis and conformational analysis of bicyclic mimics of alpha- and beta-D-glucopyranosides adopting the biologically relevant 2,5B conformation

International audienceThe synthesis of three conformationally locked D-glucopyranoside analogs displaying the hydroxyl pattern of the parent sugar is described. A two carbon bridge connecting the C-2 and C-5 atoms of the pyranose ring allows a torsion of the sugar ring toward a B-2,B-5 conformation as confirmed by conformational analysis. This conformation is strongly believed to be adopted by the oxacarbenium ion-like transition state of several inverting glucosidases