Resolution of phthalans obtained by ortho-litiathion of aryloxiranes by enantioselective high-performance liquid chromatography: Performances of various chiral stationary phases

The HPLC separation of the enantiomers of six phthalans (1,3-dihydrobenzo[c]furans) synthesized as racemic mixtures from ortho-lithiated aryloxiranes was accomplished in the normal-phase mode using seven polysaccharide-derived and Pirkle-type chiral stationary phases (CSPs) and n-hexane/2-propanol mixtures as mobile phases. Separation and resolution factors up to 1.6 and 4.2, respectively, were obtained. The performances of various CSPs with regard to the same compound were, however, quite different not only between the two types of CSPs but also within the same type (polysaccharide-derived or Pirkle-type). Also diastereomeric pairs of phthalans show different enantioseparation using the same CSP.