Enantioselective synthesis of L-phosphinothricin from L-methionine and L-glutamic acid via L-vinylglycine

Abstract

L-Phosphinothricin ( 6), a natural occurring amino acid which possesses herbicidal and antibiotical properties by inhibiting the enzyme glutamine synthetase (E.C. 6.3.1.2) in plants and bacteria, can be obtained with 99.4% enantiomeric excess via regioselective addition of alkyl methylphosphinates 4 to protected L-vinylglycine derivatives 3 followed by hydrolysis of the intermediates 5. L-Vinylglycine derivatives 3 are easily prepared from L-methionine ( 1a) and L-glutamic acid ( 1b). Protected L-vinylglycine derivatives 3 can also be used as starting materials in the enantioselective synthesis of L-2-aminobutyric acids bearing a phosphonate or phosphine oxide moiety in 4-position.