Synthesis and Characterization of some Heterocyclic Derivatives from 1,2:3,4-Di-O-isopropylidene-#alpha#-D-galacto-1,6-hexadialdo-1,5-pyranose Oxime

摘要

We report the synthesis of 5-[5'-(1',2':3',4'-di-O-isopropylidene-#beta#-L-arabinopyranosyl)]tetrazole, from 1,2:3,4-di-O-isopropylidene-#alpha#-D-galacto-1,6-hexodialdo-1,5-pyranose oxime via 1,2:3,4-di-O-isopropylidene-#alpha#-D-galacturononitrile as intermediate by 1,3-dipolar cycloaddition. We also report the synthesis of 5-methyl- and 5-phenyl-2-[5'-(1',2':3',4'- di-O-isopropylidene-#beta#-L-arabinopyranosyl)]-1,3,4-oxadiazole from the tetrazole derivative. The physical and spectroscopic characterizations of the heterocyclic derivatives as well as the intermediate nitrile and the principal byproduct are described and we discuss its possible formation pathway. We present the preferential conformation in solution using computational calculation and spectroscopic data.