Total Synthesis of Skyllamycins

Abstract

The skyllamycins are a family of highly functionalized non‐ribosomal cyclic depsipeptide natural products which contain the extremely rare α‐OH‐glycine functionality. Herein the first total synthesis of skyllamycins A–C is reported, together with the biofilm inhibitory activity of the natural products. Linear peptide precursors for each natural product were prepared through an efficient solid‐phase route incorporating a number of synthetic modified amino acids. A novel macrocyclization step between a C‐terminal amide and an N‐terminal glyoxylamide moiety served as a key transformation to install the unique α‐OH‐glycine unit and generate the natural products in the final step of the synthesis.