Synthesis of Analogues of GABA. III. All Four Stereoisomers of 3-Aminocyclopentanecarboxylic Acid and a Stereochemical Correlation with Amidinomycin

Abstract

All four stereoisomers of 3-aminocyclopentanecarboxylic acid have been prepared as analogues of the inhibitory neurotransmitter GABA. The amino acid degradation product from the antibiotic amidinomycin corresponds to cis-(1R,3S)-3-aminocyclopentanecarboxylic acid and thus amidinomycin is (1R,3S)-N-(2'-amidinoethyl)-3-aminocyclopentane-1-carboxamide (10). A key reaction was the stereoselective reduction of 3-hydroxyiminocyclopentanecarboxylic acid (8) to the corresponding cis amino acid (2).