Liquid phase peptide syntheses of KL-4 pulmonary surfactant

The present invention relates to the field of peptide syntheses and intermediates useful therein. More particularly, the invention relates to the synthesis of the polypeptide component of KL-4, a synthetic pulmonary surfactant. The invention realtes to improved liquid phase processes for the preparation of the 21 residue protein component, (Lys-Leu)-Lys, of the pulmonary surfactant KL-4. These process are amenable to large scale synthesis and one process employs a method of saponifying an ester which reduces the inherent racemization of the -carbon.