Vigabatrin (y-vinyl GABA, 4-amino-5-hexenoic acid) is a highly selective enzyme-activated inhibitor of GABA-T in mammalian brain,'which crosses the blood-brain-barrier (BBB), and is used clinically primarily to control seizures refractory to other anticonvulsant drugs.'(S)- Vigabatrin is the pharmacological active enantiomer, whereas the (R)-antipode is inactive. The two enantiomers of vigabatrin have been prepared by asymmetric syntheses,'-'or by ...