Hexamethyldisilazanes mediated one-pot intramolecular Michael addition–olefination reactions leading to exo-olefinated bicyclo[6.4.0]dodecanes

Abstract

A novel one-pot reaction for the synthesis of exo-olefinated bicyclo[6.4.0]dodecanes 23 has been developed on the basis of an intramolecular Michael reaction of phenylsulfonyl compounds 4 with potassium hexamethyldisilazide (KHMDS) and a sequential reaction with an excess of methoxymethyl chloride (MOMCl). By this reaction, an exo-olefin group was regioselectively introduced at the α-position to the carbonyl group in the 6-membered ring in high yield. The regioselective introduction of the olefin moiety could be envisaged to proceed through a Mannich-type reaction involving the aminomethylating agent 24, which, in turn, is generated in situ by the action of HMDS on MOMCl.

References

1. M. C. Wani, H. L. Taylor, M. E. Wall, P. Coggon and A. T. McPhail, J. Am. Chem. Soc., 1971, 93, 2325.
2. E. K. Rowinsky, L. A. Cazenave and R. C. Donehover, J. Natl. Cancer Inst., 1990, 82, 1247.
3. I. Ringel and S. B. Horwiz, J. Natl. Cancer Inst., 1991, 83, 288.
4. J. Kobayashi, A. Ogiwara, H. Hosoyama, H. Shigemori, N. Yoshida, T. Sasaki, Y. Li, S. Iwasaki, M. Naito and T. Tsuruno, Tetrahedron, 1994, 50, 7401; H. Morita, L. Wei, A. Gouda, K. Takeya, M. Itokawa, H. Fukaya, H. Shigemori and J. Kobayashi, Tetrahedron, 1997, 53, 4621.
5. For a recent total synthesis: K. Morihara, R. Hara, S. Kawahara, T. Nishimori, N. Nakamura, H. Kusama and I. Kuwajima, J. Am. Chem. Soc., 1998, 120, 12980 and references therein.
6. (a) For reviews, see: K. C. Nicolaou, W.-M. Dai and R. K. Guy, Angew. Chem., Int. Ed. Engl., 1994, 33, 15; B. Norton and N. Biother, Drugs Fut., 1996, 21(1), 95; (b) G. Mehta and V. Singh, Chem. Rev, 1999, 99, 881.
7. N. S. Simpkins, (a)Sulfones in Organic Chemistry, Pergamon Press, Oxford, 1993, p. 100; (b)Tetrahedron, 1990, 46, 6951.
8. A part of this work has been published as a preliminary communication: M. Ihara, S. Suzuki, Y. Tokunaga, H. Takeshita and K. Fukumoto, Chem. Commun., 1996, 1801.
9. P. Perlmutter, Conjugate Addition Reactions in Organic Synthesis, Pergamon Press, Oxford, 1992.
10. S. Arseniyadis, D. V. Yashunsky, M. M. Dorada, R. B. Alves, E. Toromano, L. Toupet and P. Potier, Tetrahedron Lett., 1993, 34, 4927.
11. This reagent was prepared from (5-bromopentyloxymethyl)benzene and triphenylphosphine in toluene under reflux for 10 h in 76% yield.
12. I. Nakagawa and T. Hata, Tetrahedron Lett., 1975, 1409; I. Nakagawa, K. Aki and T. Hata, J. Chem. Soc., Perkin Trans. 1, 1983, 1315.
13. For a review, see: S. V. Ley, J. Norman, W. P. Grith and S. P. Marsden, Synthesis, 1994, 639.
14. D. Sternbach and C. L. Ensinger, J. Org. Chem., 1990, 55, 2725.
15. R. Rappo, D. S. Allen, R. U. Lemieux and W. S. Johnson, J. Org. Chem., 1956, 21, 478.
16. The vinyl iodide 16 was obtained as a mixture of E/Z isomers (1/15).
17. G. Stork and K. Zhao, Tetrahedron Lett., 1989, 30, 2137; D. Seyferth, J. K. Heeren, G. Singh, S. O. Grim and W. B. Hughes, J. Organomet. Chem., 1966, 5, 267.
18. MCPBA (purchased from Wako Pure Chemical Co. Ltd) had to be added to the reaction mixture in one portion at 0 °C to prevent the formation of over-oxidised products.
19. J. K. Pau, J. K. Kim and M. C. Caserio, J. Am. Chem. Soc., 1978, 100, 3831, 3838; S. Okada, Y. Abe, S. Taniguchi and S. Yamabe, J. Am. Chem. Soc., 1987, 109, 295.
20. For reviews, see: M. Arend, B. Westermann and N. Risch, Angew. Chem., Int. Ed., 1998, 37, 1044; M. Tramontini, Synthesis, 1973, 703.
21. T. Morimoto, T. Takeshita and M. Sekiya, J. Chem. Soc., Chem Commun., 1984, 794, 883.