5 [5' (1',2':3',4' di o isopropylidene beta levo arabinopyranosyl]tetrazole 2 5 methyl 2 [5' (1',2':3',4' di o isoproylidene beta levo arabinosyl] 1,3,4 oxadiazole 2 5 phenyl 2 [5' (1',2':3',4' di o isoproylidene beta levo arabinosyl] 1,3,4 oxadiazole 2 article 2 carbon nuclear magnetic resonance 2 chemical reaction 2 chemical structure 2 heterocyclic compound 2 organic chemistry 2 oxadiazole derivative 2 proton nuclear magnetic resonance 2 synthesis 2 tetrazole derivative 2 unclassified drug 2