The chirality conversion reagent for amino acids based on salicyl aldehyde

2-Hydroxy-6-(1-(3-phenylurylphenyl)ethoxy)-benzaldehyde (2) has been synthesized in racemic form from 1,3-Dihydroxybenzene via formylation and reaction with 3-phenyluryl-methylbenzylbromide. The optically pure form of 2 was separated by normal silica column chromatography from the imine diastreomer which was obtained by the reaction of racemic mixture of 2 with optically pure leucinol. The absolute configuration of the separated enantiomer of 2 was decided from the energy calculation of the corresponding imine diastereomers. The activity of 2 as a chirality conversion reagent (CCR) for amino acids was determined by 1H NMR analysis. The efficiency of 2 is not better than the previous CCRs based on binaththol. Compound 2, however, has lower molecular weight compared to other CCRs. This work demonstrates that asymmetric carbon can control the selectivity of amino acids.