C-(2-Deoxy-d-arabino-hex-1-enopyranosyl)-oxadiazoles: synthesis of possible isomers and their evaluation as glycogen phosphorylase inhibitors

Abstract Synthetic methods were elaborated for d -glucals attached to oxadiazoles by a C–C bond. Introduction of the double bond was effected by either DBU induced elimination of PhCOOH from the O -perbenzoylated glucopyranosyl precursors or Zn/ N -methylimidazole mediated reductive elimination from the 1-bromoglucopyranosyl starting compounds. Alternatively, heterocyclizations of 2-deoxy- d - arabino -hex-1-enopyranosyl cyanide were also carried out. Test compounds were obtained by Zemplen debenzoylation, however, none of them showed significant inhibition of rabbit muscle glycogen phosphorylase b .