(Z)-and (E)-4-amino-2-(trifluoromethyl)-2-butenoic acid (4 and 5, respectively) were synthesized and investigated as potential mechanism-based inactivators of γ-aminobutyric acid aminotransferase (GABA-AT) in a continuing effort to map the active site of this enzyme. The core α-trifluoromethyl-α, β-unsaturated ester moiety was prepared via a Reformatsky/reductive elimination coupling of the key intermediates tert-butyl 2, 2-dichloro ...