22333-70-6

PCT No. PCT/EP96/04073 Sec. 371 Date Mar. 24, 1998 Sec. 102(e) Date Mar. 24, 1998 PCT Filed Sep. 18, 1996 PCT Pub. No. WO97/12881 PCT Pub. Date Apr. 10, 1997The invention pertains to a process for the continuous production of basic cyclic optically active alpha -amino acids of general formula (I) by continuous racemate splitting via diastereomeric salt pairs with re-racemisation of the residual amino acid or amino acid derivative in the mother liquid with the aid of an optically active acid.

Chiral diphosphines constituted by an aromatic pentatomic biheterocyclic system, suitable to act as chiral ligands, complexes between said diphosophines and transition metals, and their utilization as chiral catalysts in sterocontrolled reactions, such as diastereo- and enantioselective reduction reactions. Process for the preparation of said chiral diphosophines and process for the preparation of said complexes and for their utilization as chiral catalysts in sterocontrolled reactions.

The enantiomers of the title compound can be obtained in a simple two-step crystallization procedure starting from the racemate. The compound 2 of the calcium O,O'-dibenzoyl-tartrate formed with two molecules of 2-methoxyethanol exists as a conglomerate, making a simple enantioseparation possible.

The present invention relates to the separation of optically active phenylalanine and N-acyl derivatives thereof and novel diastereomer salts of the said compounds. According to the invention a racemic compound of the formula STR1 is reacted with an optically active resolving agent of the formula STR2 in a polar solvent and/or a mixture of solvents comprising at least one apolar solvent and optionally an achiral acid or base, thereafter (a) when using the D-isomer of the resolving agent of the formula II, the crystalline diastereomer salt formed with the L-isomer of the compound of the formula I is separated, or (b) when using the L-isomer of the resolving agent of the formula II, the crystalline diastereomer salt formed with the D-isomer of the compound of the formula I is separated, and the enantiomers of the compound of the formula I from the diastereomer salt or the mother liquor are liberated by the aid of an achiral acid or base and the optically active product is separated in crystalline form.