Enantiomers of β‐lactams bearing aryl, furyl or styryl substituents in the 4‐position were chromatographically separated by means of high‐performance liquid chromatography on chiral column packed with amino acid‐derived chiral stationary phase. Separation factors are generally modest. To improve further the resolution of enantiomers, the rings of these β‐lactams were opened with octanol in acidic conditions and converted into N‐3,5‐ dinitrobenzoyl ester derivatives of the resulting β‐amino acids. Enantiomers of these derivatives are efficiently separated on an amide‐derived chiral stationary phase. The chromatographic separations enable accurate determination of optical purity of the chiral β‐ lactams, prepared from homochiral ester enolate‐imine condensation. The absolute configuration of the major enantiomer of the β‐amino acid derivatives was determined from elution order on a chiral column.

Enantioselective synthesis of optically active p-lactam via ester enol ate-imine condensation using homochiral ester 16 and imine 17 providedji-lactam 18a in 77% ec. Lactam 18a, carried C(3) functionality onp-lactam nuclei, provided a potential precursor toward a synthesis of dipeptide antibiotic.