AMINO-ACIDS AND PEPTIDES .40. SYNTHESIS OF AC-TYR-VAL-ALA-ASP-MCA USING NEWLY DEVELOPED ACETYLATING

2-Acetoxy-3-benzyl-5-methyl-6-isobutylpyrazine was prepared by cycliza tion of H-Phe-Leu-CH2,Cl, followed by acetylation with acetic anhydrid e. This pyrazine derivative can react with amino groups of amino acids or peptides to produce acetyl amino acids or acetyl peptides without acetylation of hydroxy group of Tyr, Ser and Thr. Using this acetylati ng reagent, Ac-Tyr-Val-Ala-Asp-MCA, which is a specific substrate of t he interleukin-I (IL-I) processing enzyme, was prepared.