The protected nonapeptide, N~-carbobenzoxy-N~-t-butyloxycarbonyllysylprolylvalylglycyl- N~-~-butyloxy-carbonyllysyl-N~-t-butyloxycarbonyllysyl-N~-tosylarginyl-N~-tosylarginyl- baminovaleric acid methyl ester, has been synthesized by a stepwise procedure. The