Enantioseparation of α-Hydroxyallylphosphonates and Phosphonoallylic Carbonate Derivatives on Chiral Stationary Phases Using Sequential UV, Polarimetric, and Refractive Index Detection

Chromatographic separation of the enantiomers of parent compounds dimethyl α-hydroxyallyl phosphonate 1a and 1-(dimethoxyphosphoryl) allyl methyl carbonate 1b was demonstrated by high-performance liquid chromatography (HPLC) using Chiralpak AS-H and ad-H chiral stationary phases (CSP), respectively, using a combination of UV, polarimetric, and refractive index detectors. A comparison was made of the separation efficiency and elution order of enantiomeric α-hydroxyallyl phosphonates and their carbonate derivatives on commercially available polysaccharide AS, ad, OD, IC-3, and Whelk-O 1 CSPs. In general, the α-hydroxyallyl phosphonates were resolved on the AS-H CSP, whereas the carbonate derivatives 1b and 2b were preferentially resolved on the ad-H CSP. The impact of aryl substitution on the resolution of analytes 1d, 1e, 1f and 2, 3, 4, 5, 6, 7, 8 was evaluated. Thermodynamic parameters determined for enantioselective adsorption hydroxyphosphonates 1a and 4 on the AS-H CSP and carbonate 1b on the ad-H CSP demonstrated enthalpic control for separation of the enantiomers. Chirality 28:656–662, 2016.