Quantum Chemical Study on Chiral Recognition Modes Between Esters of a-Hydroxy­carboxylic Acids and Amino Acids

Authors:

• Marcin Maciej Hoffmann

Abstract

Chiral recognition between methyl ester of (R)-lactic acid and (R)- or (S)-alanine hasbeen studied by means of quantum chemistry. The interacting systemsin vacuohave beenstudied up to B3LYP/6-311++G(3df,3pd)//B3LYP/6-31+G(d) and MP2/6-31+G(d) lev-els, while aqueous solution effects have been includedviasolvation model SM5.4 calcu-lations. The obtained results shed new light on chiral recognition between homochiraland heterochirala-hydroxy carboxylic acid esters and amino acids. Energy of binding byabout 3 kJ/mol favors associations between homochiral (R + R) molecules of methyl es-ter of lactic acid and alanine then associations between heterochiral (R + S) molecules. Inthe heterochiral complex alaninie accommodates significantly larger deformation than inthe homochiral association