CYCLOLS‐FORMATION FROM TRIPEPTIDE SYSTEMS AND STRUCTURE ASSIGNMENT BY CARBON‐13 NUCLEAR MAGNETIC RESONANCE

The influence of the nature of the amino acids on the cyclolization reaction, starting from linear tripeptides, has been studied. In these systems the presence of proline at the carboxyl end as well as the alkyl substitution on the other two residues have been found to be important. The utilization of 13C-NMR spectroscopy as a direct method for detecting the cyclolic structure is reported.