Collect. Czech. Chem. Commun. 1989, 54, 3360-3373

Ammonolysis mediated side reactions of β-tert-butyl aspartyl peptides

István Schön and Attila Rill

Chemical Works of Gedeon Richter, Ltd., Lajos Kisfaludy Research Laboratory, H-1475 Budapest, P.O/ Box 27, Hungary


Ammonolysis of Z-Asp(OBut)-Phe-NH2 and Boc-Leu-Asp(OBut)-Phe-NH2, as well as their diastereomers, resulted not only in transpeptidated, but also in epimerized peptides through a complex mechanism. Key compounds of these transformations are presumably very reactive cyclic aminosuccinyl derivatives. In some cases, the amount of α-peptide formed approached that of the β-peptide, in one case it exceeded this amount.