Synfacts 2018; 14(11): 1111
DOI: 10.1055/s-0037-1611235
Synthesis of Natural Products and Potential Drugs
© Georg Thieme Verlag Stuttgart · New York

Synthesis of (–)-Asperchalasine A

Contributor(s):
Erick M. Carreira
,
Niels Sievertsen
Long X, Ding Y, Deng J. * Kunming Institute of Botany and University of Chinese Academy of Sciences, Beijing, P. R. of China
Total Synthesis of Asperchalasines A, D, E and H.

Angew. Chem. Int. Ed. 2018;
DOI: DOI: 10.1002/anie.201808481.
Further Information

Publication History

Publication Date:
18 October 2018 (online)

 

Significance

The unique cytochalasan dimer ­asperchalasine A, which possesses a decacyclic ring system and twenty chiral centers, was among cytochalasan alkaloids recently isolated from the culture broth of Aspergillus flavipes. Deng and co-workers took on the synthetic challenges associated with the preparation of the structurally ­intriguing asperchalasines A in the laboratory and report its first total synthesis. Furthermore, asperchalasines D, E, and H were accessed from shared intermediates.


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Comment

The enantioselective synthesis began with the preparation of triene segment C and dienophile D from l-arabinose and Boc-l-leucine, respectively. Diels–Alder cyclo­addition crafted intermediate E, which was elaborated further to give 17-epi-aspochalasin B (H). Diels–Alder reaction of this tricycle with epicoccine-derived I provided hexacycle J, which was subsequently converted into the target structure by formal [5+2] cycloaddition with an additional equivalent of H.


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