A New Synthesis of Glutamic Acid*

Glutamic acid has been prepared previously by the racemization (1) of the natural dextro form and by three synthetic methods. The first synthesis, that by Wolff (2) in 1890, is principally of theoretical interest as it involves the preparation of six intermediate substances starting with levulinic acid and the yield of final product is not given. In 1925 Knoop and Oesterlin (3) obtained 1.1 gm. (23 per cent yield) of glutamic acid from (Yketoglutaric acid and alcoholic ammonia with hydrogen and palladium black as reducing agents. In the same year Keimatsu and Sugasawa (4) reported a synthesis with acrolein as starting material. None of these methods appears to be as satisfactory as the method described herewith. The following reactions are involved in the present synthesis of glutamic acid.