ZnCl2-mediated practical protocol for the synthesis of Amadori ketoses.

An efficient and practical protocol for the synthesis of Amadori ketoses N-(1-deoxy-D-fructose-1-yl) amino acid (amino acid=L-valine (1), L-leucine (2), L-isoleucine (3), L-tryptophan (4), L-phenylalanine (5), L-arginine (6) has been accomplished by employing ZnCl2 as a catalyst. The developed method circumvents protection and deprotection steps as well as tedious ion-exchange and column chromatographic techniques. The accomplished Amadori ketoses showed moderate to weak angiotensin I converting enzyme (ACE) inhibitory activity.