Synthesis of Unsaturated Analogues of Glutamic Acid: Amination of Trianions From Unsaturated Dicarboxylic Acids With Chloramine

Abstract

Trianions can be formed from dicarboxylic acids which contain a β,γ -double bond, and amination with chloramine yields β,γ-unsaturated α-amino acids. This methodology provides a convenient synthesis of amino acids that are inaccessible by other routes. (Z)-3-Phenylthiopent-2-enedioic acid and all four stable unsaturated analogues of the conformationally restricted glutamate analogue 1-aminocyclopentane-1,3-dicarboxylic acid have been synthesized to demonstrate the applicability of the method. The structure of one of the amino acid products, (±)-cis-1-aminocyclopent-4-ene-1,3-dicarboxylic acid (7), has been determined; it crystallizes in the space group P2₁/c, a 9.245(24), b 8.455(2), c 9.311(3) Ǻ, β 95.00(2)°, and the structure was refined to R 0.035 for 980 F.