Resolution of α-cyclohexyl mandelic acid enantiomers by enantioselective extraction in separation system containing tartaric esters and β-cyclodextrin

AimTo establish a resolution method for α-cyclohexyl mandelic acid enantiomers by enantioselective extraction and to observe the effects of all kinds of tartaric esters, pH, the concentration of D-tartaric esters and β-cyclodextrin on the enantioselectivity. MethodsResolution of α-cyclohexyl mandelic acid enantiomers by enantioselective extraction with tartaric esters and β-cyclodextrin has been studied. ResultsThe distribution behavior of α-cyclohexyl mandelic acid enantiomers in the separation system was studied. The effects of all kinds of tartaric esters, pH, the concentration of D-tartaric esters and β-cyclodextrin on the enantioselectivity has been examined in the two-phase. ConclusionResults showed that the complex formed by D-iso-butyl-D-tartaric ester with R enantiomer is stabler than that with S enantiomer. With the increase of pH, the partition coefficient and separation factor decreased. The concentration of β-cyclodextrin and D-tartaric ester had visible effect on the enantioselectivity.