ISSN print edition: 0366-6352 ISSN electronic edition: 1336-9075 Registr. No.: MK SR 9/7 Published monthly

Enantioseparation of mandelic acid and α-cyclohexylmandelic acid using an alcohol/salt-based aqueous two-phase system

Fen-Fang Li, Zhi-Jian Tan, and Zhi-Feng Guo

School of Chemistry and Chemical Engineering, Central South University, Changsha, 410083, China

E-mail: lfflqq@mail.csu.edu.cn

Abstract: An alcohol/salt-based aqueous two-phase system (ATPS) was employed for enantioseparation of (R,S)-mandelic acid (MA) and (R,S)-α-cyclohexylmandelic acid (α-CHMA). Sulfonated β-cyclodextrin (Sf-β-CD) with different degrees of substitution (DS) was considered as the chiral selector. The ethanol/(NH₄)₂SO₄ system showed the optimal chiral recognition ability for MA. To optimize the experimental conditions, Sf-β-CD concentration, ethanol and salt concentration, temperature, and pH were studied. The recognition ability of enantiomers was mainly dependent on the type of the chiral selector but the ethanol and (NH₄)₂SO₄ concentrations also had significant influence on the enantiomeric recognition. The maximum values of α and ee ^up of 1.69 and 16.3 % were obtained, respectively, for MA under the optimal conditions. A potential application of this alcohol/salt ATPS is the scale-up of chiral separation of MA.

Keywords: alcohol/salt aqueous two-phase system – chiral separation – enantiomers – sulfonated β-cyclodextrin

Full paper is available at www.springerlink.com.

DOI: 10.2478/s11696-014-0594-y

Chemical Papers 68 (11) 1539–1545 (2014)