First enantiocontrolled synthesis of sceletium alkaloid A-4: determination of the absolute configuration

Abstract

Sceletium A-4, a pyridine alkaloid isolated from the Sceletium species, has been synthesized for the first time in an enantiocontrolled manner along with (–)-mesembrine, an alkaloid isolated from the same plant, starting from a chiral cyclohexadienone synthon to determine the absolute configuration.

References

1. A. Popelak and G. Lettenbauer, in The Alkaloids, ed. R. H. F. Manske, Academic Press, New York, 1967, vol. IX, p. 467.
2. (a) P. W. Jeffs, P. A. Luhan, A. T. McPhail and N. H. Martin, J. Soc., Chem. Commun., 1971, 1466; (b) F. O. Snyckers, F. Strelow and A. Wiechers, J. Chem. Soc., Chem. Commun., 1971, 1467; (c) P. A. Luhan and A. T. McPhail, J. Chem. Soc., Perkin Trans. 2, 1972, 2006; (d) P. W. Jeffs, T. Capps, D. B. Johnson, J. M. Karle, N. H. Martin and B. Rauckman, J. Org. Chem., 1974, 39, 2703.
3. R. V. Stevens, P. M. Lesko and R. Lapalme, J. Org. Chem., 1975, 40, 3495; P. N. Confalone and E. M. Huie, J. Am. Chem. Soc., 1984, 106, 7175.
4. P. Coggon, D. S. Farrier, P. W. Jeffs and A. T. McPhail, J. Chem. Soc. (B), 1970, 1267.
5. S. Takano, Y. Imamura and K. Ogasawara, Tetrahedron Lett., 1981, 22, 4479.
6. K. Ogasawara, Pure Appl. Chem., 1994, 66, 2119.
7. S. Takano, Y. Higashi, T. Kamikubo, M. Moriya and K. Ogasawara, Synthesis, 1993, 948; K. Hiroya, Y. Kurihara and K. Ogasawara, Angew Chem., Int. Ed. Engl., 1995, 34, 2287.
8. M. Shimizu, T. Kamikubo and K. Ogasawara, Tetrahedron: Asymmetry, 1997, 8, 2519.
9. A. P. Kozikowski and S. H. Jung, J. Org. Chem., 1986, 51, 3402.
10. Y. Horiguchi, S. Matsuzawa and I. Kuwajima, Tetrahedron Lett., 1986, 4025.
11. S. Takano, K. Inomata and K. Ogasawara, J. Chem. Soc., Chem. Commun., 1992, 169.
12. M. Saito, M. Kawamura, K. Hiroya and K. Ogasawara, Chem. Commun., 1997, 765.
13. G. Stork and K. Zhao, Tetrahedron Lett., 1989, 30, 287.
14. O. Mitsunobu, Synthesis, 1981, 1; D. L. Hughes, Org. React., 1972, 42, 335.
15. C. R. Johnson, P. A. Adams, M. P. Braun, C. B. W. Senanayake, P. M. Wovkulich and M. R. Uskokovic, Tetrahedron Lett., 1992, 33, 917.
16. K. Sonogashira, Y. Toda and N. Hagiwara, Tetrahedron Lett., 1975, 4467.
17. W. S. Emerson, Org. React., 1948, 4, 174.