手性酯类萃取剂萃取拆分α-环己基扁桃酸外消旋体

Chiral Extraction of Racemic α-cyclohexyl-mandelic Acid with Tartaric Acid Esters as Chiral Selector

研究了α-环己基扁桃酸对映体在含有疏水性D酒石酸酯手性选择体的1,2-二氯乙烷和水两相系统萃取分配行为,考察了酒石酸酯烷基链长度、pH值和D酒石酸酯浓度对分配比和分离因子的影响。实验表明:D酒石酸酯与R-α-环己基扁桃酸对映体比与S-α-环己基扁桃酸对映体形成更稳定的非对映体复合物;随着pH值增大,分配比减小,分离因子也随之降低;同时,D酒石酸酯浓度的影响也比较大。

The distribution behavior of α-cyclohexyl-mandelic acid enantiomers was examined in a twophase aqueous - organic solvent mixture containing tartaric acid esters. The effects of pH, alkyl chain length of tartaric acid esters and the concentrations of D-tartaric acid esters on the partition coefficients and separation factors were investigated. The results showed that the D-tartaric acid esters studied all formed more stable diastereomeric complexes with R-enantiomer than with S-enantiomer, and that the partition coefficients（K） and the separation factors（a） decreaseed with the increase of pH. The influence of the concentrations of D-tartaric acid esters on K and a was insignificant.