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Enantioselective Total Synthesis of (+)-Gelsemine

Enantioselective Total Synthesis of (+)-Gelsemine. YOKOSHIMA, s.; Tokuyama, H.; Fukuyama, T. Angew . Chem . Int. Ed. 2000 , 39 , 4073-4075 . A presentation BY Guillaume Pelletier. (+)-Gelsemine. Isolated from gelsemium sempervirens . Its structure was determined in 1959 by Conroy

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Enantioselective Total Synthesis of (+)-Gelsemine

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  1. Enantioselective Total Synthesis of (+)-Gelsemine YOKOSHIMA, s.; Tokuyama, H.; Fukuyama, T. Angew. Chem. Int. Ed. 2000,39, 4073-4075. A presentation BY Guillaume Pelletier

  2. (+)-Gelsemine Isolatedfromgelsemiumsempervirens. Its structure wasdetermined in 1959 by Conroy and Chakrabarti by degrative and spectroscopic data. Crystallographicdetermination by Lovell et al. No (or sketchy) biologicalactivity. 7 total syntheis of Gelsemine up to date. Lin, H.; Danishefsky, S. J. Angew. Chem. Int. Ed. 2003, 42, 36-51.

  3. Racemic Gelsemine Synthesis 3 Racemic total synthesis before the synthesis of Fukuyama: Lin, H.; Danishefsky, S. J. Angew. Chem. Int. Ed. 2003, 42, 36-51.

  4. Retrosynthetic analysis by Fukuyama Yokoshima, S.; Tokuyama, H.; Fukuyama, T. Angew. Chem. Int. Ed. 2000, 39, 4073-4075.

  5. Steps 1-3 Yokoshima, S.; Tokuyama, H.; Fukuyama, T. Angew. Chem. Int. Ed. 2000, 39, 4073-4075.

  6. Diels-Alderwith Evans’ oxazolidinone Evans, D. A.; Chapman, K. T.; Bisaha, J. J. Am. Chem. Soc. 1988, 110, 1238-1256

  7. Steps 1-3 Yokoshima, S.; Tokuyama, H.; Fukuyama, T. Angew. Chem. Int. Ed. 2000, 39, 4073-4075.

  8. Steps 1-3 Yokoshima, S.; Tokuyama, H.; Fukuyama, T. Angew. Chem. Int. Ed. 2000, 39, 4073-4075.

  9. Tamao-Fleming oxidation Jones, G. R.; Landais, Y. Tetrahedron1996, 52, 7599-7662.

  10. Steps 4-7 Yokoshima, S.; Tokuyama, H.; Fukuyama, T. Angew. Chem. Int. Ed. 2000, 39, 4073-4075.

  11. Lewis acid – catalyzedcationic fragmentation Maruoka, K.; Itoh, T.; Sakurai, M.; Nonoshita, K.; Yamamoto, H. J. Am. Chem. Soc. 1988, 110, 3588-3591

  12. Synthesis of 4-iodooxindole Fukuyama, T.; Liu, G. J. Am. Chem. Soc.1996, 118, 7426-7427.

  13. Steps 4-7 Yokoshima, S.; Tokuyama, H.; Fukuyama, T. Angew. Chem. Int. Ed. 2000, 39, 4073-4075.

  14. Condensation withoxoindole

  15. Steps 4-7 Yokoshima, S.; Tokuyama, H.; Fukuyama, T. Angew. Chem. Int. Ed. 2000, 39, 4073-4075.

  16. Steps 8-13 Yokoshima, S.; Tokuyama, H.; Fukuyama, T. Angew. Chem. Int. Ed. 2000, 39, 4073-4075.

  17. Divinylcyclopropanerearrangement (Cope)

  18. Steps 8-13 Yokoshima, S.; Tokuyama, H.; Fukuyama, T. Angew. Chem. Int. Ed. 2000, 39, 4073-4075.

  19. Horner-WadsworthEmmonds Minami, T.; Okauchi, T.; Kouno, R. Synthesis2001, 349-357.

  20. Steps 8-13 Yokoshima, S.; Tokuyama, H.; Fukuyama, T. Angew. Chem. Int. Ed. 2000, 39, 4073-4075.

  21. Radical dehalogenation

  22. Steps 14 to 20 Yokoshima, S.; Tokuyama, H.; Fukuyama, T. Angew. Chem. Int. Ed. 2000, 39, 4073-4075.

  23. Steps 21 to 25 Yokoshima, S.; Tokuyama, H.; Fukuyama, T. Angew. Chem. Int. Ed. 2000, 39, 4073-4075.

  24. Grieco’sprocedure – Seleno-dehydradtion Grieco, P. A.; Gilman. S.; Nishizawa, M. J. Org. Chem. 1976, 41, 1485.

  25. Steps 21 to 25 Yokoshima, S.; Tokuyama, H.; Fukuyama, T. Angew. Chem. Int. Ed. 2000, 39, 4073-4075.

  26. PolonovskiReaction Sundberg, R. J.; Gadamasetti, K. G.; Hunt, P. J. Tetrahedron 1992, 48, 277-296

  27. PolonovskiReaction Sundberg, R. J.; Gadamasetti, K. G.; Hunt, P. J. Tetrahedron 1992, 48, 277-296

  28. Polonovski – likeelimination Yokoshima, T.; Kubo, T.; Tokuyama, H.; Fukuyama, T. Chem. Lett. 2002, 122-123.

  29. Steps 26 to (+)-Gelsemine Yokoshima, S.; Tokuyama, H.; Fukuyama, T. Angew. Chem. Int. Ed. 2000, 39, 4073-4075.

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