The reaction of d-glucose with aminoguanidine

The reaction of d-glucose with aminoguanidine was examined at pH 7.0 and 37°C (phosphate buffer). Under these conditions, the reaction requires ca. 42 days for 50% of the sugar to react, as measured by the disappearance of d-glucose, and at 60°C all the aminoguanidine had reacted within 72 h. The initial product, a β- d-glucopyranosyl aminoguanidine ( 1) was obtained in the crystalline state as the trifluoroacetate salt. Data collected on this compound suggests that, in solution, it is largely a glycosylamine in the β pyranose form. Acetylation gave a crystalline heptaacetate ( 2), which, in solution (as evidenced by NMR spectroscopy) exists in two different conformational forms. The crystal structure of the heptaacetate also includes two conformers. Both crystallographically independent molecules are in the normal β pyranose form, with the acetylated guanyl residue occupying different spatial positions relative to the ring.