Sequential oligopeptides. Synthesis and characterization of the oligopeptides and a polypeptide with the repeating sequence L‐norvalyl‐glycyl‐L‐proline

The synthesis and characterization of a series of oligopeptides (from the tripeptide to the octadecapeptide) with the repeating sequence L ‐norvalyl‐glycyl‐ L ‐proline and a polytripeptide with this sequence are reported. The oligomers were synthesized step by step using the mixed anhydride method. All the products were chemically and optically pure. The polymer was prepared by the active ester method, using the p ‐nitrophenyl ester as the polymerizable tripeptide derivative. Good yield of relatively high average molecular‐weight polymer was obtained. In the accompanying paper conformational investigations, both in solution and in the solid state, on the oligomers and the polymer are described.