Chromatographic resolution of some cyclic sulfoximides derived from prochiral and chiral sulfoxides

Three endocyclic sulfoximides of the 1‐aryl‐ and 1‐alkyl‐3‐oxo‐benzo[ d ]‐isothia (IV)‐azole 1‐oxide type (1‐substituent = 2′‐carboxyphenyl, 2′‐carbethoxyphenyl, and octyl, respectively) were found to be well resolved on a chiral phase derived from bovine serum albumin (BSA). Selectivities (α) of 1.74, 1.12, and 1.44, respectively, were obtained. The retention behaviour of 1‐octyl‐3‐oxo‐benzo[ d ]isothia(IV)‐azole 1‐oxide was further investigated in some detail as a function of the mobile phase composition and the elution order was established from optically active material obtained from the enantiopure sulfoxide precursor. An enantiomeric excess of 85.4% was obtained in the cyclocondensation reaction of the octyl‐substituted sulfoxide precursor with hydrazoic acid to the corresponding endocyclic sulfoximide. © 1995 Wiley‐Liss, Inc.