Fibrinopeptides. II. Synthesis of protected hexapeptide sequence (5-​10) of human fibrinopeptide-​A

Abstract

The protected hexapeptide sequence (5-​10) of human fibrinopeptide-​A, BOC-​Glu(OBzl)​-​Gly-​Asp(OBzl)​-​Phe-​Leu-​Ala-​OMe (BOC = Me3CO2C, Bzl = PhCH2) (I)​, was synthesized using the mixed anhydride (MA)​, dicyclohexylcarbodiimide (DCC)​, 2,​4,​5-​trichlorophenyl ester (OCP) and pentachlorophenyl ester (OPCP) methods. The OCP method was applicable only after the tripeptide stage. The overall yield of I from the DCC, MA and OPCP methods was 23.2, 20.5 and 18.7​%, resp