PRACTICAL SYNTHESIS OF L-ERYTHRO-4-FLUOROGLUTAMIC AND L-THREO-4-FLUOROGLUTAMIC ACIDS USING AMINOACYLASE

Enantiomerically pure L-erythro- and L-threo-4-fluoroglutamic acids 1a and 1b were conveniently prepared. The key steps in this synthesis re lied upon separation of diastereomers of N-chloroacetyl-4-fluoroglutam ic acid 5-methyl ester 7 by recrystallization and enzymatic resolution of enantiomers of the resulting 7(a+c) and 7(b+d) by aminoacylase. Pr otection of the gamma-carboxyl group as a methyl ester was found to be crucial for this enzymatic reaction. Copyright (C) 1996 Elsevier Scie nce Ltd.