Synthesis of the protected 6–16 segment of zervamicin II‐2, an application of the azirine/oxazolone method

The protected 11 amino acid segment (6–16) of the peptaibol zervamicin II‐2 was synthesized by using the ‘azirine/oxazolone method’ for the introduction of all Aib residues. Whereas a 2,2‐dimethyl‐2 H ‐azirin‐3‐amine was used as the building block for Aib(7), methyl 2,2‐dimethyl‐2 H ‐azirine‐3‐prolinate and ‐3‐(3‐hydroxyprolinate) proved to be ideally suited as dipeptide synthons for the introduction of Aib‐Pro and Aib‐Hyp, respectively. The coupling of Z‐protected amino acids or peptide acids with the 2 H ‐azirin‐3‐amines were performed in 75% to quantitative yield. Copyright © 2003 European Peptide Society and John Wiley & Sons, Ltd.