The enantiomers of syn-2,3-difluoro-4-aminobutyric acid elicit opposite responses at the GABA(C) receptor.

The conformational behaviour and GABA receptor activity of the different stereoisomers of 2,3-difluoro-4-aminobutyric acid are described. Two enantiomeric GABA(C)-active ligands are identified, one of which is an agonist while the other is an antagonist. The results support an existing QSAR model of the bioactive geometry of GABA at GABA(C).