Abstract: | Peptide synthesis by Means of ‘Push-Pull’-Acetylenes ‘Push-pull’-acetylenes 1 are excellent reagents for peptide synthesis: Addition of ‘push-pull’-acetylenes to solutions of N-protected amino acids (or vice versa) gives enol esters 5 , which react selectively with the amino function of a second amino acid. In this way serine, tyrosine, 4-hydroxyproline, cysteine as well as histidine are linked to form dipeptide esters without protection of the second functional group (OH, SH or NH). The amount of racemization is very low. Similarly tri- as well as tetrapeptides are available. The versatility of the reaction is discussed. |