Erysodienone

Structure of erysodienone and its proposed biosynthetic pathway
Biomimetic synthesis of erysodienone.

Erysodienone is a key precursor in the biosynthesis of many Erythrina-produced alkaloids.[1] Early work was done by Derek Barton and co-workers to illustrate the biosynthetic pathways towards erythrina alkaloids.[2][3][4] It was demonstrated that erysodienone could be synthesized from simple starting materials by a similar approach as its biosynthetic pathway, which lead to the development of the biomimetic synthesis of erysodienone.[5]

Synthesis

The biosynthesis of erysodienone involves a key step of oxidative phenol coupling. Starting with S-norprotosinomenine precursor A, cyclization via oxidative phenol coupling forms intermediate B, which in turn can be rearranged to form intermediate C. Hydrogenation of C forms the diphenoquinone intermediate E. An intramolecular Michael addition reaction converts E to the final product, erysodienone.[6]

A biomimetic synthesis route for erysodienone was developed based on a similar oxidative phenol coupling mechanism. Barton and co-workers[7] found that treating bisphenolethylamine precursor F with oxidants such as K3Fe(CN)6 initiated oxidative phenol coupling to form the 9-membered ring structure in intermediate D that itself undergo a Michael addition to give erysodienone.[8]

References

  1. ↑ Rahman, Mohammed Z., et al. "Phytochemical and biological investigations of Erythrina variegata." Saudi Pharmaceutical Journal 15.2 (2007): 140.
  2. ↑ Barton, D. H. R.; Boar, R. B.; Widdowson, D. A. J. Chem. Soc. C 1970, 1213.
  3. ↑ Barton, D. H. R.; Potter, C. J.; Widdowson, D. A. J. Chem. Soc. Perkin. Trans. 1974, 1346.
  4. ↑ Barton, D. H. R.; James, R.; Kirby, G. W.; Turner, D. W.; Widdowson, D. A. J. Chem. Soc. C 1968, 1529.
  5. ↑ Herbert, R. B. (1985). "The Biosynthesis of Isoquinoline Alkaloids": 213–228. doi:10.1007/978-3-642-70128-3_14. ISSN 0172-6625.
  6. ↑ Maier UH, Rödl W, Deus-Neumann B, Zenk MH (1999). "Biosynthesis of Erythrina alkaloids in Erythrina crista-galli.". Phytochemistry 52 (3): 373–82. doi:10.1016/s0031-9422(99)00230-7. PMID 10501023.
  7. ↑ Barton, D. H. R.; Boar, R. B.; Widdowson, D. A. J. Chem. Soc. C 1970, 1208
  8. ↑ M. F. Grundon (1 January 1979). The Alkaloids:. Royal Society of Chemistry. pp. 16–. ISBN 978-0-85186-660-4.

Further Reading

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