Synthesis of analogues of GABA. VI. Stereoisomers of cis-3-Aminocyclohexanecarboxylic acid

Abstract

The syntheses are described of (1R,3S)- and (1S,3R)-3-aminocyclohexanecarboxylic acids via unsaturated intermediates suitable for tritium labelling. The absolute stereochemistry was determined by an alternative synthesis of the (1R,3S) isomer from (R)-3-oxocyclohexanecarboxylic acid. The (1S,3R) isomer showed a similar potency to GABA as an inhibitor of the uptake of radioactive GABA by rat brain slices whereas the (1R,3S) isomer was at least 20 times less potent.