Enantiomeric enrichment of partially resolved 4-hydroxy-2-carboxymethylcyclopentanone de derivatives by achiral phase chromatography

Abstract

Enantiomeric purity of the chromatographic peaks of partially resolved ( R)-4-hydroxy-2-carboxymethyl-2-cyclopentenone ( 4) ( R)-4-hydroxy-2-methoxycarbonylmethyl-2-cyclopentenone ( 2), ( S)-4-benzoyloxy-2-carboxymethyl-2-cyclopentenone ( 5), ( R)-4-methoxy-2-carboxymethyl-2-cyclopentenone ( 6, ( R)-4-methoxy-2-methoxycarbonylmethyl-2-cyclopentenone ( 7) and (−)-5-oxa-6-oxoprostaglandin E 1 C(15) epimers ( 1A) and ( 1B) in achiral normal-phase chromatography on silica gel is dependent on the fraction which is being examined. The mentioned substances exhibit an enantiomer enrichment at the beginning of the chromatographic peak and a gradual depletion in the following parts. The observed enantiomer enrichment effect can be explained by a mechanistic concept which assumes a preferred association between the antipodes of the solute.