VI yielded with phosphorus pentachloride,@-benzyl-N-carboxy-L-aspartate anhydride (IV). This reaction is known to cause no change in steric configuration.'IV polymerized upon heating to poly-(6-benzyl-L-aspartate)(V) which was reduced with phosphonium iodide to poly-L-aspartic acid (VI),[a]*%-11.2'(c, 5 in water containing one equiva-lent of sodium hydroxide). From VI, L-aspartic acid was obtained in quantitative yield upon acid ...
[Parr, Ian B.; Boehlein, Susan K.; Dribben, Anthony B.; Schuster, Sheldon M.; Richards, Nigel G. J. Journal of Medicinal Chemistry, 1996 , vol. 39, # 12 p. 2367 - 2378]
