Ein neues 3‐Amino‐2 H ‐azirin als Aib‐Pro‐Baustein: Synthese des C‐terminalen Nonapeptids von Trichovirin I 1B

A New 3‐Amino‐2 H ‐azirine as an Aib‐Pro Synthon: Synthesis of the C‐Terminal Nonapeptide of Trichovirin I 1B The synthesis of methyl N ‐(2,2‐dimethyl‐2 H ‐azirin‐3‐yl)‐ L ‐prolinate ( 3 ), a novel 3‐amino‐2 H ‐azirine, is described ( Scheme 2 ). It is shown that the reaction of COCl 2 with thioamide 5 is remarkably faster than with the corresponding amide 4 , and the yield of 3 is much better in the synthesis starting with 5 . The 3‐amino‐2 H ‐azirine 3 has been used as a building block of the dipeptide moieties Aib‐Pro in the synthesis of nonapeptide 17 ( Schemes 4 and 5 ), the C‐terminal 6–14 segment of the peptaibole trichovirin I 1B. The structure of 17 was established by single‐crystal X‐ray crystallography ( Figs.1 and 2 ).