Synthesis of peptides containing 1,2,3,4-tetrahydroquinoline-2-carboxylic acid. Part 1. Absolute configurations of 1,2,3,4-tetrahydroquinoline-2-carboxylic acids and 2-substituted 1,2,3,4-tetrahydroquinolines

Abstract

(–)-1,2,3,4-Tetrahydroquinoline-2-carboxylic acid was isolated by oxidation of the racemic amino-acid with D-amino-acid oxidase; (+)-1,2,3,4-tetrahydroquinoline-2-carboxylic acid, obtained from hydrolysis of the dipeptide (+)-N-benzyloxycarbonyl-(S)-phenylalanyl-1,2,3,4-tetrahydroquinoline-2-carboxylic acid, was chemically correlated with (–)-1,2,3,4-tetrahydro-2-methylquinoline through (–)-(R)-β-anilinobutyric acid, the configuration of which was also established. The absolute configuration of (–)-1,2,3,4-tetrahydroquinoline-2-carboxylic acid and (–)-1,2,3,4-tetrahydro-2-methylquinoline is shown to be S.