ENANTIOMERIC SEPARATION OF RACEMIC THIOSULPHINATE ESTERS BY HIGH-PERFORMANCE LIQUID-CHROMATOGRAPHY

High-performance liquid chromatographic methods using chiral stationary phases were developed for the separation of racemic mixtures of biologically active alk(en)ylsulphinothioic acid alk(en)yl esters (syn. thiosulphinate esters, ts) from natural (Allium cepa L.) or synthetic origin. Aromatic substituted thiosulfinate esters could be baseline resolved using helical (+)-poly(triphenylmethyl methacrylate)-coated silica gel [Chiralpak OT (+)] as chiral stationary phase and methanol as eluent. A correlation between chromatographic resolution and the structures of the thiosulphinate esters could be established. A preparative separation of diphenyl-ts was achieved with cellulose triacetate (CTA) as the stationary phase. The elution sequence of diphenyl-ts enantiomers on the CTA column is reversed when compared to that on the Chiralpak OT (+).