High selective autocatalytic esterification of glutamic acid by benzyl alcohol with CuCl2 promoting.

Abstract: We found that the esterification of l-glutamic acid by benzyl alcohol is greatly promoted by CuCl2 even in H2O solvent, and the selectivity and yield of γ-benzyl ester of l-glutamic acid achieved 100% and 95.31%. Metal cation coordination to the amino acids via neighboring amino and carbonyl groups increased α position carboxyl acidity which initiates the esterification reaction to selectively take place on γ position carboxyl group. In this autocatalytic process H2O has no effect on esterification. [Copyright &y& Elsevier]