Efforts toward the first total synthesis of a mixed-ligand siderophore: Gobichelin-A.

The synthesis of Gobichelin-A, a naturally occurring mixed-ligand siderophore isolated from Streptomyces sp. NRRL F-4415, is described. The target molecule was planned to be synthesized by a convergent process involving the combination of two halves, Gob-A 1st half and Gob-A 2nd half, at the prefinal stage of the synthetic route. By adopting this method, fully protected Gobichelin-A was synthesized in excellent yield.