A Synthesis of <scp>l</scp>-Proline from <scp>l</scp>-Glutamine

Abstract

Abstract 1. Novel syntheses of optically active proline and ornithine from optically active glutamine are described. 2. Carbobenzoxy-l-glutamine esters were dehydrated to γ-cyano-α-l-carbobenzoxyaminobutyric acid esters with p-toluenesulfonyl chloride, phosphorous oxychloride or thionyl chloride. 3. Hydrogenation of γ-cyano-α-l-carbobenzoxyaminobutyric acid esters in aqueous solvent systems were effected by silk-palladium catalyst to yield mainly l-proline. 4. By hydrogenation in the presence of Raney nickel in non-aqueous solvent, l-ornithine was obtained.