The natural product himastatin has an unusual homodimeric structure that presents a substantial synthetic challenge. We report the concise total synthesis of himastatin from readily accessible precursors, incorporating a final-stage dimerization strategy that was inspired by a detailed consideration of the compound’s biogenesis. Combining this approach with a modular synthesis enabled expedient access to more than a dozen designed derivatives of himastatin, including synthetic probes that provide insight into its antibiotic activity.
Movassaghi, Mohammad,Pentelute, Bradley L.,Schissel, Carly K.,D’Angelo, Kyan A.
p. 894 - 899
(2022/03/02)
Discovery through total synthesis: A retrospective on the himastatin problem
A total synthesis of a structure proposed for himastatin was accomplished. The non-identity of the fully synthetic material with himastatin necessitated a revision of the assigned structure. Confirmation of the revised stereostructure was subsequently confirmed through total synthesis. Among the achievements during this effort were i) stereospecific routes to both anti-cis and syn-cis pyrrolindoline substructures; ii) a practical synthesis to 5-hydroxypiperazic acid in enantiomerically pure form; iii) a Stille coupling leading to a complex bi-indole moiety,and iv) efficient protecting group management throughout the evolving depsipeptide domain. The outlines for a biological pharmacophore have been delineated. The alternating D- and L-substituents in the 6-mer as well as the biaryl linkage connecting the two identical subunits are critical for maintaining biological activity. This pattern is simulated in another antibiotic, and suggests a possible structural trend for future SAR investigations.
Kamenecka, Theodore M.,Danishefsky, Samuel J.
p. 41 - 63
(2007/10/03)
Total synthesis of himastatin: Confirmation of the revised stereostructure
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Kamenecka, Theodore M.,Danishefsky, Samuel J.
p. 2995 - 2998
(2007/10/03)
Studies in the total synthesis of himastatin: A revision of the stereochemical assignment
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