Synthesis of a key intermediate in the diaminopimelate pathway to L-lysine: 2,3,4,5-tetrahydrodipicolinic acid

Article abstract of DOI:10.1016/0040-4020(95)00618-I

2,3,4,5-Tetrahydrodipicolinic acid (3) is a key intermediate in the diaminopimelate (DAP) pathway to L-lysine (7). It was synthesized as the stable racemic potassium salt (25) from dipicolinic acid (14) by esterification, hydrogenation to the cis-diester (17), followed by elimination of p-toluenesulfinic acid from the N-toluenesulfonyl derivative (24) of dimethyl cis-piperidine-2,6-dicarboxylate with concomitant cleavage of the esther groups. (±)-2,3,4,5-Tetrahydrodipicolinic acid is unstable in neutral or acidic solution, and in basic solution it exists in equilibrium with the corresponding enamine (27) and 2-oxo-6-aminoadipate (26).