Total Synthesis of Himastatin: Confirmation of the Revised Stereostructure

Abstract

A stereoisomer of the natural product and not himastatin, an unusual dimeric depsipeptide with promising antibiotic and antitumor properties, was obtained from pyrroloindoline anti-cis-1. This result led to a revision of the proposed stereostructure. The new stereostructure was confirmed by the total synthesis, which involves stereoselective access to the pyrroloindoline syn-cis-1 and the 5-hydroxypiperazic acid subunit and features a Stille coupling for the formation of the central carbon–carbon bond.