Peptidsynthesen unter verwendung der 2‐(p‐diphenyl)‐isopropyl‐oxycarbonyl (dpoc)‐aminoschutzgruppe

Abstract The 2‐( p ‐diphenyl)‐isopropyloxycarbonyl (Dpoc) residue has been chosen for the selective protection of α‐amino groups in the synthesis of peptides containing additional acid‐labile protecting residues. It is easily introduced into amino‐acids by reacting either the mixed carbonate I or the azide III with esters or salts of amino‐acids. It is split by dilute acetic acid and other weakly acidic reagents at rates which permit a selective cleavage in the presence of other acid‐labile protecting groups, especially those derived from t ‐butanol A number of peptide syntheses have been carried out with the new group either in the conventional manner or by the solid‐phase method. No effects due to steric hindrance, as observed previously with the N‐trityl residue, are encountered. The application of the Nα‐Dpoc group to solid‐phase peptide synthesis permits the use of a new combination of protecting groups in which the side chains of trifunctional amino‐acids are blocked by acid‐labile residues that can be easily split in the final step of the synthesis.