| abstract |
An industrially advantageous production process which is an improved process for the production of an optically active α-amino-ϵ-caprolactam (ACL). By the process, a desired optically active isomer having a high optical purity can be obtained with the aid of an optical resolver available at low cost in a large amount. An optically active phenylalanine derivative, in particular, N-p-toluenesulfonyl-L-phenylalanine, is used as a resolver to optically resolve DL-ACL by the diastereomeric method. A solvent having a permittivity suitably selected is used as a reaction medium for this optical resolution to precipitate a diastereomeric salt. Thus, a diastereomeric salt containing D-ACL or L-ACL can be selectively obtained. |