Thermal cycloaddition reactions of azulene-1,5-quinones and azulene-1,7-quinones with cyclic dienes and cycloheptatriene

Abstract

[2+4]-[6+4] Cycloadducts were obtained from the thermal cycloaddition reactions of azulenequinones with cyclic 4π systems such as 1,3-diphenylisobenzofuran and isobenzofuran while the reaction of cycloheptatriene and azulenequinones gave ene products as well as cage molecules. The first addition site of 1,3-diphenylisobenzofuran was different for 3-bromoazulene-1,5-quinone and azulene-1,5-quinone; the former reacted on the cyclopentenone part and the latter on the C-6–C-7 bond to avoid formation of an unstable cyclopentadienone structure.

References

1. L. T. Scott, M. D. Rozeboom, K. N. Houk, T. Fukunaga, H. J. Lindner and K. Hafner, J. Am. Chem. Soc., 1980, 102, 5169.
2. L. T. Scott, P. Grütter and R. E. Chamberlain, III, J. Am. Chem. Soc., 1984, 106, 4852.
3. L. T. Scott and C. M. Adams, J. Am. Chem. Soc., 1984, 106, 4857.
4. The term [m+n] denotes the mode of the cycloaddition between the mπ component of the azulenequinone and the nπ component of the counterpart.
5. T. Nozoe, H. Wakabayashi, K. Shindo, T. Kurihara, S. Ishikawa and M. Kageyama, Chem. Lett., 1995, 25; T. Nozoe, H. Wakabayashi, K. Shindo and S. Ishikawa, Chem. Lett., 1995, 27.
6. T. Nozoe, H. Takeshita, Y. Z. Yan and A. Mori, Synlett, 1995, 375; A. Mori, Y. Z. Yan, H. Takeshita and T. Nozoe, J. Chem. Soc., Perkin Trans. 1, 1998, 3219.
7. T. Nozoe and H. Takeshita, Bull. Chem. Soc. Jpn., 1996, 69, 1149.
8. H. Takeshita, Y. Z. Yan, N. Kato, A. Mori, H. Wakabayashi and T. Nozoe, Tetrahedron Lett., 1995, 29, 5199.
9. H. Takeshita, Y. Z. Yan, N. Kato, A. Mori and T. Nozoe, Tetrahedron Lett., 1995, 29, 5195.
10. H. Takeshita, Y. Wada, A. Mori and T. Hatsui, Chem. Lett., 1973, 335.
11. T. Hatsui, M. Matono and K. Yanagi, Nippon Kagaku Kaishi, 1971, 92, 1260 (Chem. Abstr., 1972, 77, 87294k).
12. S. Itô, Y. Fujise and M. C. Woods, Tetrahedron Lett., 1967, 1059; Y. Fukazawa, S. Itô and Y. Iitaka, Acta Crystallogr., Sect. B, 1969, 25, 665.
13. R. B. Woodward and R. Hoffmann, The Conservation of Orbital Symmetry, Verlag Chemie GmbH, Weinheim, 1970, p. 126.
14. There are several examples of [8+2] cycloadducts involving the tropone carbonyl group; e.g., H. Takeshita, H. Nakashima, S. Sugiyama and A. Mori, Bull. Chem. Soc. Jpn., 1988, 61, 573.
15. T. Machiguchi, T. Hasegawa, S. Itoh and H. Mizuno, J. Am. Chem. Soc., 1989, 111, 1920.
16. K. N. Houk and R. B. Woodward, J. Am. Chem. Soc., 1989, 111, 1920.
17. W. R. Roth and A. Friedrich, Tetrahedron Lett., 1969, 2607.
18. M. C. Altomare, M. Burla, G. Camalli, C. Cascarano, A. Giacovazzo, G. Guagliardi and J. Polidori, J. Appl. Crystallogr., 1994, 27, 435.
19. G. M. Sheldrick, SHELXL93. Program for the Refinement of Crystal Structures, University of Göttingen, Germany, 1993.