Metal-Mediated [6 + 3] Cycloaddition Reactions of Fulvenes. A Novel Approach to Indan Systems

Journal of Organic Chemistry

Volumn 62, Issue 22, 1997, Pages 7717-7725

  Hong, Bor Cherng ^a   Sun, Si Shoung ^a   Tsai, Yann Chien ^a  

^a NATIONAL CHUNG CHENG UNIVERSITY   (Taiwan)

Author keywords

[No Author keywords available]

Indexed keywords

EID: 0001488132     PISSN: 00223263     EISSN: None     Source Type: Journal    
DOI: 10.1021/jo970984j     Document Type: Article

References (84)

1. For an interesting historical note on the discovery of the Diels- Alder reaction, see: Berson, J. A. Tetrahedron, 1992, 48, 3.
2. For examples of [2 + 2 + 2] cycloadditions, see: (a) Vollhardt, K. P. C. Angew. Chem. Int. Ed. Engl. 1984, 23, 539-556. (b) Brown, S.; Clarkson, S.; Grigg, R.; Sridharan, V. Tetrahedron Lett. 1993, 34, 157-160. (c) Trost, B. M.; Tanoury, G. J. J. Am. Chem. Soc. 1987, 109, 4753-4755. (d) Hoberg, H.; Oster, B. W. Synthesis, 1982, 324-325. (e) Grigg, R.; Scott, R.; Stevenson, P. J. Chem. Soc., Perkin Trans 1 1988, 1357-1364.
3. For examples of [2 + 2 + 2] cycloadditions, see: (a) Vollhardt, K. P. C. Angew. Chem. Int. Ed. Engl. 1984, 23, 539-556. (b) Brown, S.; Clarkson, S.; Grigg, R.; Sridharan, V. Tetrahedron Lett. 1993, 34, 157-160. (c) Trost, B. M.; Tanoury, G. J. J. Am. Chem. Soc. 1987, 109, 4753-4755. (d) Hoberg, H.; Oster, B. W. Synthesis, 1982, 324-325. (e) Grigg, R.; Scott, R.; Stevenson, P. J. Chem. Soc., Perkin Trans 1 1988, 1357-1364.
4. For examples of [2 + 2 + 2] cycloadditions, see: (a) Vollhardt, K. P. C. Angew. Chem. Int. Ed. Engl. 1984, 23, 539-556. (b) Brown, S.; Clarkson, S.; Grigg, R.; Sridharan, V. Tetrahedron Lett. 1993, 34, 157-160. (c) Trost, B. M.; Tanoury, G. J. J. Am. Chem. Soc. 1987, 109, 4753-4755. (d) Hoberg, H.; Oster, B. W. Synthesis, 1982, 324-325. (e) Grigg, R.; Scott, R.; Stevenson, P. J. Chem. Soc., Perkin Trans 1 1988, 1357-1364.
5. For examples of [2 + 2 + 2] cycloadditions, see: (a) Vollhardt, K. P. C. Angew. Chem. Int. Ed. Engl. 1984, 23, 539-556. (b) Brown, S.; Clarkson, S.; Grigg, R.; Sridharan, V. Tetrahedron Lett. 1993, 34, 157-160. (c) Trost, B. M.; Tanoury, G. J. J. Am. Chem. Soc. 1987, 109, 4753-4755. (d) Hoberg, H.; Oster, B. W. Synthesis, 1982, 324-325. (e) Grigg, R.; Scott, R.; Stevenson, P. J. Chem. Soc., Perkin Trans 1 1988, 1357-1364.
6. For examples of [2 + 2 + 2] cycloadditions, see: (a) Vollhardt, K. P. C. Angew. Chem. Int. Ed. Engl. 1984, 23, 539-556. (b) Brown, S.; Clarkson, S.; Grigg, R.; Sridharan, V. Tetrahedron Lett. 1993, 34, 157-160. (c) Trost, B. M.; Tanoury, G. J. J. Am. Chem. Soc. 1987, 109, 4753-4755. (d) Hoberg, H.; Oster, B. W. Synthesis, 1982, 324-325. (e) Grigg, R.; Scott, R.; Stevenson, P. J. Chem. Soc., Perkin Trans 1 1988, 1357-1364.
7. For examples of heteroatom [3 + 3] cycloadditions, see: (a) Mori, M.; Sugiyama, T.; Nojima, M.; Kusabayashi, S.; McCullough, K. J. J. Org. Chem. 1992, 57, 7, 2285-2294. (b) Bambal, R. B.; Kemmitt, R. D. W. J. Organomet. Chem. 1989, 362, C18-C20. (c) Pearson, W. H.; Fang, W.; Kampf, J. W. J. Org. Chem. 1994, 59, 2682-2684. (d) Bonini, B. F.; Maccagnani, G.; Mazzanti, G.; Zwanenburg, B. J. Chem. Soc., Chem. Commun. 1985, 237-238. (e) Tominaga, Y.; Ueda, H.; Ogata, K.; Kohra, S. J. Heterocycl. Chem. 1992, 29, 209-214.
8. For examples of heteroatom [3 + 3] cycloadditions, see: (a) Mori, M.; Sugiyama, T.; Nojima, M.; Kusabayashi, S.; McCullough, K. J. J. Org. Chem. 1992, 57, 7, 2285-2294. (b) Bambal, R. B.; Kemmitt, R. D. W. J. Organomet. Chem. 1989, 362, C18-C20. (c) Pearson, W. H.; Fang, W.; Kampf, J. W. J. Org. Chem. 1994, 59, 2682-2684. (d) Bonini, B. F.; Maccagnani, G.; Mazzanti, G.; Zwanenburg, B. J. Chem. Soc., Chem. Commun. 1985, 237-238. (e) Tominaga, Y.; Ueda, H.; Ogata, K.; Kohra, S. J. Heterocycl. Chem. 1992, 29, 209-214.
9. For examples of heteroatom [3 + 3] cycloadditions, see: (a) Mori, M.; Sugiyama, T.; Nojima, M.; Kusabayashi, S.; McCullough, K. J. J. Org. Chem. 1992, 57, 7, 2285-2294. (b) Bambal, R. B.; Kemmitt, R. D. W. J. Organomet. Chem. 1989, 362, C18-C20. (c) Pearson, W. H.; Fang, W.; Kampf, J. W. J. Org. Chem. 1994, 59, 2682-2684. (d) Bonini, B. F.; Maccagnani, G.; Mazzanti, G.; Zwanenburg, B. J. Chem. Soc., Chem. Commun. 1985, 237-238. (e) Tominaga, Y.; Ueda, H.; Ogata, K.; Kohra, S. J. Heterocycl. Chem. 1992, 29, 209-214.
10. For examples of heteroatom [3 + 3] cycloadditions, see: (a) Mori, M.; Sugiyama, T.; Nojima, M.; Kusabayashi, S.; McCullough, K. J. J. Org. Chem. 1992, 57, 7, 2285-2294. (b) Bambal, R. B.; Kemmitt, R. D. W. J. Organomet. Chem. 1989, 362, C18-C20. (c) Pearson, W. H.; Fang, W.; Kampf, J. W. J. Org. Chem. 1994, 59, 2682-2684. (d) Bonini, B. F.; Maccagnani, G.; Mazzanti, G.; Zwanenburg, B. J. Chem. Soc., Chem. Commun. 1985, 237-238. (e) Tominaga, Y.; Ueda, H.; Ogata, K.; Kohra, S. J. Heterocycl. Chem. 1992, 29, 209-214.
11. For examples of heteroatom [3 + 3] cycloadditions, see: (a) Mori, M.; Sugiyama, T.; Nojima, M.; Kusabayashi, S.; McCullough, K. J. J. Org. Chem. 1992, 57, 7, 2285-2294. (b) Bambal, R. B.; Kemmitt, R. D. W. J. Organomet. Chem. 1989, 362, C18-C20. (c) Pearson, W. H.; Fang, W.; Kampf, J. W. J. Org. Chem. 1994, 59, 2682-2684. (d) Bonini, B. F.; Maccagnani, G.; Mazzanti, G.; Zwanenburg, B. J. Chem. Soc., Chem. Commun. 1985, 237-238. (e) Tominaga, Y.; Ueda, H.; Ogata, K.; Kohra, S. J. Heterocycl. Chem. 1992, 29, 209-214.
12. For examples of [3 + 3] annulations, see: (a) Ward, D. E.; Gai, Y.; Kaller, B. F. J. Org. Chem. 1995, 60, 7830. (b) Seebach, D.; Missbach, M.; Calderari, G.; Eberle, M. J. Am. Chem. Soc. 1990, 112, 7625-7638. (c) Meyer, W. L.; Brannon, M. J.; Merritt, A.; Seebach, D. Tetrahedron Lett. 1986, 27, 1449-1452. (d) Chan, T. H.; Kang, G. J. Terahedron Lett. 1983, 24, 3051-3054. (e) Lu, Xiyan, Huang, Y. Tetrahedron Lett. 1986, 27, 1615-1616. (f) Sands, R. D. J. Org. Chem. 1983, 48, 3362-3363. Anzeveno, P. B.; Matthews, D. P. Charlotte, L. B.; Barbuch, R. J. Tetrahedron Lett. 1984, 49, 3134-3138. Chan, T.- H.; Brownbridge, P. J. Am. Chem. Soc. 1980, 102, 3534-3538. Molander, G. A.; Shubert, D. C. J. Am. Chem. Soc. 1987, 109, 576- 578.
13. For examples of [3 + 3] annulations, see: (a) Ward, D. E.; Gai, Y.; Kaller, B. F. J. Org. Chem. 1995, 60, 7830. (b) Seebach, D.; Missbach, M.; Calderari, G.; Eberle, M. J. Am. Chem. Soc. 1990, 112, 7625-7638. (c) Meyer, W. L.; Brannon, M. J.; Merritt, A.; Seebach, D. Tetrahedron Lett. 1986, 27, 1449-1452. (d) Chan, T. H.; Kang, G. J. Terahedron Lett. 1983, 24, 3051-3054. (e) Lu, Xiyan, Huang, Y. Tetrahedron Lett. 1986, 27, 1615-1616. (f) Sands, R. D. J. Org. Chem. 1983, 48, 3362-3363. Anzeveno, P. B.; Matthews, D. P. Charlotte, L. B.; Barbuch, R. J. Tetrahedron Lett. 1984, 49, 3134-3138. Chan, T.- H.; Brownbridge, P. J. Am. Chem. Soc. 1980, 102, 3534-3538. Molander, G. A.; Shubert, D. C. J. Am. Chem. Soc. 1987, 109, 576- 578.
14. For examples of [3 + 3] annulations, see: (a) Ward, D. E.; Gai, Y.; Kaller, B. F. J. Org. Chem. 1995, 60, 7830. (b) Seebach, D.; Missbach, M.; Calderari, G.; Eberle, M. J. Am. Chem. Soc. 1990, 112, 7625-7638. (c) Meyer, W. L.; Brannon, M. J.; Merritt, A.; Seebach, D. Tetrahedron Lett. 1986, 27, 1449-1452. (d) Chan, T. H.; Kang, G. J. Terahedron Lett. 1983, 24, 3051-3054. (e) Lu, Xiyan, Huang, Y. Tetrahedron Lett. 1986, 27, 1615-1616. (f) Sands, R. D. J. Org. Chem. 1983, 48, 3362-3363. Anzeveno, P. B.; Matthews, D. P. Charlotte, L. B.; Barbuch, R. J. Tetrahedron Lett. 1984, 49, 3134-3138. Chan, T.- H.; Brownbridge, P. J. Am. Chem. Soc. 1980, 102, 3534-3538. Molander, G. A.; Shubert, D. C. J. Am. Chem. Soc. 1987, 109, 576- 578.
15. For examples of [3 + 3] annulations, see: (a) Ward, D. E.; Gai, Y.; Kaller, B. F. J. Org. Chem. 1995, 60, 7830. (b) Seebach, D.; Missbach, M.; Calderari, G.; Eberle, M. J. Am. Chem. Soc. 1990, 112, 7625-7638. (c) Meyer, W. L.; Brannon, M. J.; Merritt, A.; Seebach, D. Tetrahedron Lett. 1986, 27, 1449-1452. (d) Chan, T. H.; Kang, G. J. Terahedron Lett. 1983, 24, 3051-3054. (e) Lu, Xiyan, Huang, Y. Tetrahedron Lett. 1986, 27, 1615-1616. (f) Sands, R. D. J. Org. Chem. 1983, 48, 3362-3363. Anzeveno, P. B.; Matthews, D. P. Charlotte, L. B.; Barbuch, R. J. Tetrahedron Lett. 1984, 49, 3134-3138. Chan, T.- H.; Brownbridge, P. J. Am. Chem. Soc. 1980, 102, 3534-3538. Molander, G. A.; Shubert, D. C. J. Am. Chem. Soc. 1987, 109, 576- 578.
16. For examples of [3 + 3] annulations, see: (a) Ward, D. E.; Gai, Y.; Kaller, B. F. J. Org. Chem. 1995, 60, 7830. (b) Seebach, D.; Missbach, M.; Calderari, G.; Eberle, M. J. Am. Chem. Soc. 1990, 112, 7625-7638. (c) Meyer, W. L.; Brannon, M. J.; Merritt, A.; Seebach, D. Tetrahedron Lett. 1986, 27, 1449-1452. (d) Chan, T. H.; Kang, G. J. Terahedron Lett. 1983, 24, 3051-3054. (e) Lu, Xiyan, Huang, Y. Tetrahedron Lett. 1986, 27, 1615-1616. (f) Sands, R. D. J. Org. Chem. 1983, 48, 3362-3363. Anzeveno, P. B.; Matthews, D. P. Charlotte, L. B.; Barbuch, R. J. Tetrahedron Lett. 1984, 49, 3134-3138. Chan, T.- H.; Brownbridge, P. J. Am. Chem. Soc. 1980, 102, 3534-3538. Molander, G. A.; Shubert, D. C. J. Am. Chem. Soc. 1987, 109, 576- 578.
17. For examples of [3 + 3] annulations, see: (a) Ward, D. E.; Gai, Y.; Kaller, B. F. J. Org. Chem. 1995, 60, 7830. (b) Seebach, D.; Missbach, M.; Calderari, G.; Eberle, M. J. Am. Chem. Soc. 1990, 112, 7625-7638. (c) Meyer, W. L.; Brannon, M. J.; Merritt, A.; Seebach, D. Tetrahedron Lett. 1986, 27, 1449-1452. (d) Chan, T. H.; Kang, G. J. Terahedron Lett. 1983, 24, 3051-3054. (e) Lu, Xiyan, Huang, Y. Tetrahedron Lett. 1986, 27, 1615-1616. (f) Sands, R. D. J. Org. Chem. 1983, 48, 3362-3363. Anzeveno, P. B.; Matthews, D. P. Charlotte, L. B.; Barbuch, R. J. Tetrahedron Lett. 1984, 49, 3134-3138. Chan, T.- H.; Brownbridge, P. J. Am. Chem. Soc. 1980, 102, 3534-3538. Molander, G. A.; Shubert, D. C. J. Am. Chem. Soc. 1987, 109, 576- 578.
18. For examples of [3 + 3] annulations, see: (a) Ward, D. E.; Gai, Y.; Kaller, B. F. J. Org. Chem. 1995, 60, 7830. (b) Seebach, D.; Missbach, M.; Calderari, G.; Eberle, M. J. Am. Chem. Soc. 1990, 112, 7625-7638. (c) Meyer, W. L.; Brannon, M. J.; Merritt, A.; Seebach, D. Tetrahedron Lett. 1986, 27, 1449-1452. (d) Chan, T. H.; Kang, G. J. Terahedron Lett. 1983, 24, 3051-3054. (e) Lu, Xiyan, Huang, Y. Tetrahedron Lett. 1986, 27, 1615-1616. (f) Sands, R. D. J. Org. Chem. 1983, 48, 3362-3363. Anzeveno, P. B.; Matthews, D. P. Charlotte, L. B.; Barbuch, R. J. Tetrahedron Lett. 1984, 49, 3134-3138. Chan, T.- H.; Brownbridge, P. J. Am. Chem. Soc. 1980, 102, 3534-3538. Molander, G. A.; Shubert, D. C. J. Am. Chem. Soc. 1987, 109, 576- 578.
19. For examples of [3 + 3] annulations, see: (a) Ward, D. E.; Gai, Y.; Kaller, B. F. J. Org. Chem. 1995, 60, 7830. (b) Seebach, D.; Missbach, M.; Calderari, G.; Eberle, M. J. Am. Chem. Soc. 1990, 112, 7625-7638. (c) Meyer, W. L.; Brannon, M. J.; Merritt, A.; Seebach, D. Tetrahedron Lett. 1986, 27, 1449-1452. (d) Chan, T. H.; Kang, G. J. Terahedron Lett. 1983, 24, 3051-3054. (e) Lu, Xiyan, Huang, Y. Tetrahedron Lett. 1986, 27, 1615-1616. (f) Sands, R. D. J. Org. Chem. 1983, 48, 3362-3363. Anzeveno, P. B.; Matthews, D. P. Charlotte, L. B.; Barbuch, R. J. Tetrahedron Lett. 1984, 49, 3134-3138. Chan, T.- H.; Brownbridge, P. J. Am. Chem. Soc. 1980, 102, 3534-3538. Molander, G. A.; Shubert, D. C. J. Am. Chem. Soc. 1987, 109, 576- 578.
20. For examples of [3 + 3] annulations, see: (a) Ward, D. E.; Gai, Y.; Kaller, B. F. J. Org. Chem. 1995, 60, 7830. (b) Seebach, D.; Missbach, M.; Calderari, G.; Eberle, M. J. Am. Chem. Soc. 1990, 112, 7625-7638. (c) Meyer, W. L.; Brannon, M. J.; Merritt, A.; Seebach, D. Tetrahedron Lett. 1986, 27, 1449-1452. (d) Chan, T. H.; Kang, G. J. Terahedron Lett. 1983, 24, 3051-3054. (e) Lu, Xiyan, Huang, Y. Tetrahedron Lett. 1986, 27, 1615-1616. (f) Sands, R. D. J. Org. Chem. 1983, 48, 3362-3363. Anzeveno, P. B.; Matthews, D. P. Charlotte, L. B.; Barbuch, R. J. Tetrahedron Lett. 1984, 49, 3134-3138. Chan, T.- H.; Brownbridge, P. J. Am. Chem. Soc. 1980, 102, 3534-3538. Molander, G. A.; Shubert, D. C. J. Am. Chem. Soc. 1987, 109, 576- 578.
21. Alternatively, [6 + 1], [5 + 2], and [4 + 3] cycloadditions lead to 7-membered rings. For examples and lead references, see: (I) [6 + 1]: Ye, T.; McKervey, M. A. Chem. Rev. (Washington, D.C.) 1994, 94, 1091. [5 + 2]: (a) Sánchez, I. H.; Yáñez, R.; Enríquez, R.; Joseph-Nathan, P. J. Org. Chem. 1981, 46, 2818. (b) Sammes, P. G. Gazz. Chim. Ital. 1986, 116, 109. (c) Wender, P. A.; Lee. H. Y.; Wilhelm, R. S.; Williams, P. D. J. Am. Chem. Soc. 1989, 111, 8954. (d) Padwa, A.; Hornbuckel, S. F.; Fryxell, G. E.; Stull, P. D. J. Org. Chem. 1992, 57, 5747. (e) Wender, P. A.; Siggel, L.; Nuss, J. M. In Comprehensive Organic Synthesis; Trost, B. M., Fleming, I., Paquette, L. A., Eds.; Pergamon Press: New York, 1991; Vol 5, p 645-673. (f) Wender, P. A.; Takahashi, H.; Witulski, B. J. Am. Chem. Soc. 1995, 117, 4720. [4 + 3]: (a) Norori, R. Acc. Chem. Res 1979, 12, 61. (b) Hoffmann, H. M. R. Angew. Chem., Int. Ed. Engl. 1984, 23, 1. (c) Mann, J. Tetrahedron 1986, 421, 4611. (d) Harmata, M.; Elahmad, S. Tetrahedron Lett. 1993, 34, 789. (e) Giguere, R. J.; Tassely, S. M.; Rose, M. I.; Krishnamurthy, V. V. Tetrahedron Lett. 1990, 31, 4577. (f) Trost, B. M.; Schneider, S. Angew. Chem. Int. Ed. Engl. 1989, 28, 213. Binger, P.; Buch, H. M. Top. Curr. Chem. 1987, 135, 77. (g) Davies, H. M. L. Tetrahedron 1993, 49, 5203. (h) Hosomi, A.; Tominaga, Y. in Comprehensive Organic Synthesis; Trost, B. M., Fleming, I. Paquette, L. A., Eds.; Pergamon Press: New York, 1991; Vol 5, pp 593-615. (i) Boger, D. L.; Brotherton, C. E. J. Org. Chem. 1985, 50, 3425.
22. Alternatively, [6 + 1], [5 + 2], and [4 + 3] cycloadditions lead to 7-membered rings. For examples and lead references, see: (I) [6 + 1]: Ye, T.; McKervey, M. A. Chem. Rev. (Washington, D.C.) 1994, 94, 1091. [5 + 2]: (a) Sánchez, I. H.; Yáñez, R.; Enríquez, R.; Joseph-Nathan, P. J. Org. Chem. 1981, 46, 2818. (b) Sammes, P. G. Gazz. Chim. Ital. 1986, 116, 109. (c) Wender, P. A.; Lee. H. Y.; Wilhelm, R. S.; Williams, P. D. J. Am. Chem. Soc. 1989, 111, 8954. (d) Padwa, A.; Hornbuckel, S. F.; Fryxell, G. E.; Stull, P. D. J. Org. Chem. 1992, 57, 5747. (e) Wender, P. A.; Siggel, L.; Nuss, J. M. In Comprehensive Organic Synthesis; Trost, B. M., Fleming, I., Paquette, L. A., Eds.; Pergamon Press: New York, 1991; Vol 5, p 645-673. (f) Wender, P. A.; Takahashi, H.; Witulski, B. J. Am. Chem. Soc. 1995, 117, 4720. [4 + 3]: (a) Norori, R. Acc. Chem. Res 1979, 12, 61. (b) Hoffmann, H. M. R. Angew. Chem., Int. Ed. Engl. 1984, 23, 1. (c) Mann, J. Tetrahedron 1986, 421, 4611. (d) Harmata, M.; Elahmad, S. Tetrahedron Lett. 1993, 34, 789. (e) Giguere, R. J.; Tassely, S. M.; Rose, M. I.; Krishnamurthy, V. V. Tetrahedron Lett. 1990, 31, 4577. (f) Trost, B. M.; Schneider, S. Angew. Chem. Int. Ed. Engl. 1989, 28, 213. Binger, P.; Buch, H. M. Top. Curr. Chem. 1987, 135, 77. (g) Davies, H. M. L. Tetrahedron 1993, 49, 5203. (h) Hosomi, A.; Tominaga, Y. in Comprehensive Organic Synthesis; Trost, B. M., Fleming, I. Paquette, L. A., Eds.; Pergamon Press: New York, 1991; Vol 5, pp 593-615. (i) Boger, D. L.; Brotherton, C. E. J. Org. Chem. 1985, 50, 3425.
23. Alternatively, [6 + 1], [5 + 2], and [4 + 3] cycloadditions lead to 7-membered rings. For examples and lead references, see: (I) [6 + 1]: Ye, T.; McKervey, M. A. Chem. Rev. (Washington, D.C.) 1994, 94, 1091. [5 + 2]: (a) Sánchez, I. H.; Yáñez, R.; Enríquez, R.; Joseph-Nathan, P. J. Org. Chem. 1981, 46, 2818. (b) Sammes, P. G. Gazz. Chim. Ital. 1986, 116, 109. (c) Wender, P. A.; Lee. H. Y.; Wilhelm, R. S.; Williams, P. D. J. Am. Chem. Soc. 1989, 111, 8954. (d) Padwa, A.; Hornbuckel, S. F.; Fryxell, G. E.; Stull, P. D. J. Org. Chem. 1992, 57, 5747. (e) Wender, P. A.; Siggel, L.; Nuss, J. M. In Comprehensive Organic Synthesis; Trost, B. M., Fleming, I., Paquette, L. A., Eds.; Pergamon Press: New York, 1991; Vol 5, p 645-673. (f) Wender, P. A.; Takahashi, H.; Witulski, B. J. Am. Chem. Soc. 1995, 117, 4720. [4 + 3]: (a) Norori, R. Acc. Chem. Res 1979, 12, 61. (b) Hoffmann, H. M. R. Angew. Chem., Int. Ed. Engl. 1984, 23, 1. (c) Mann, J. Tetrahedron 1986, 421, 4611. (d) Harmata, M.; Elahmad, S. Tetrahedron Lett. 1993, 34, 789. (e) Giguere, R. J.; Tassely, S. M.; Rose, M. I.; Krishnamurthy, V. V. Tetrahedron Lett. 1990, 31, 4577. (f) Trost, B. M.; Schneider, S. Angew. Chem. Int. Ed. Engl. 1989, 28, 213. Binger, P.; Buch, H. M. Top. Curr. Chem. 1987, 135, 77. (g) Davies, H. M. L. Tetrahedron 1993, 49, 5203. (h) Hosomi, A.; Tominaga, Y. in Comprehensive Organic Synthesis; Trost, B. M., Fleming, I. Paquette, L. A., Eds.; Pergamon Press: New York, 1991; Vol 5, pp 593-615. (i) Boger, D. L.; Brotherton, C. E. J. Org. Chem. 1985, 50, 3425.
24. Alternatively, [6 + 1], [5 + 2], and [4 + 3] cycloadditions lead to 7-membered rings. For examples and lead references, see: (I) [6 + 1]: Ye, T.; McKervey, M. A. Chem. Rev. (Washington, D.C.) 1994, 94, 1091. [5 + 2]: (a) Sánchez, I. H.; Yáñez, R.; Enríquez, R.; Joseph-Nathan, P. J. Org. Chem. 1981, 46, 2818. (b) Sammes, P. G. Gazz. Chim. Ital. 1986, 116, 109. (c) Wender, P. A.; Lee. H. Y.; Wilhelm, R. S.; Williams, P. D. J. Am. Chem. Soc. 1989, 111, 8954. (d) Padwa, A.; Hornbuckel, S. F.; Fryxell, G. E.; Stull, P. D. J. Org. Chem. 1992, 57, 5747. (e) Wender, P. A.; Siggel, L.; Nuss, J. M. In Comprehensive Organic Synthesis; Trost, B. M., Fleming, I., Paquette, L. A., Eds.; Pergamon Press: New York, 1991; Vol 5, p 645-673. (f) Wender, P. A.; Takahashi, H.; Witulski, B. J. Am. Chem. Soc. 1995, 117, 4720. [4 + 3]: (a) Norori, R. Acc. Chem. Res 1979, 12, 61. (b) Hoffmann, H. M. R. Angew. Chem., Int. Ed. Engl. 1984, 23, 1. (c) Mann, J. Tetrahedron 1986, 421, 4611. (d) Harmata, M.; Elahmad, S. Tetrahedron Lett. 1993, 34, 789. (e) Giguere, R. J.; Tassely, S. M.; Rose, M. I.; Krishnamurthy, V. V. Tetrahedron Lett. 1990, 31, 4577. (f) Trost, B. M.; Schneider, S. Angew. Chem. Int. Ed. Engl. 1989, 28, 213. Binger, P.; Buch, H. M. Top. Curr. Chem. 1987, 135, 77. (g) Davies, H. M. L. Tetrahedron 1993, 49, 5203. (h) Hosomi, A.; Tominaga, Y. in Comprehensive Organic Synthesis; Trost, B. M., Fleming, I. Paquette, L. A., Eds.; Pergamon Press: New York, 1991; Vol 5, pp 593-615. (i) Boger, D. L.; Brotherton, C. E. J. Org. Chem. 1985, 50, 3425.
25. Alternatively, [6 + 1], [5 + 2], and [4 + 3] cycloadditions lead to 7-membered rings. For examples and lead references, see: (I) [6 + 1]: Ye, T.; McKervey, M. A. Chem. Rev. (Washington, D.C.) 1994, 94, 1091. [5 + 2]: (a) Sánchez, I. H.; Yáñez, R.; Enríquez, R.; Joseph-Nathan, P. J. Org. Chem. 1981, 46, 2818. (b) Sammes, P. G. Gazz. Chim. Ital. 1986, 116, 109. (c) Wender, P. A.; Lee. H. Y.; Wilhelm, R. S.; Williams, P. D. J. Am. Chem. Soc. 1989, 111, 8954. (d) Padwa, A.; Hornbuckel, S. F.; Fryxell, G. E.; Stull, P. D. J. Org. Chem. 1992, 57, 5747. (e) Wender, P. A.; Siggel, L.; Nuss, J. M. In Comprehensive Organic Synthesis; Trost, B. M., Fleming, I., Paquette, L. A., Eds.; Pergamon Press: New York, 1991; Vol 5, p 645-673. (f) Wender, P. A.; Takahashi, H.; Witulski, B. J. Am. Chem. Soc. 1995, 117, 4720. [4 + 3]: (a) Norori, R. Acc. Chem. Res 1979, 12, 61. (b) Hoffmann, H. M. R. Angew. Chem., Int. Ed. Engl. 1984, 23, 1. (c) Mann, J. Tetrahedron 1986, 421, 4611. (d) Harmata, M.; Elahmad, S. Tetrahedron Lett. 1993, 34, 789. (e) Giguere, R. J.; Tassely, S. M.; Rose, M. I.; Krishnamurthy, V. V. Tetrahedron Lett. 1990, 31, 4577. (f) Trost, B. M.; Schneider, S. Angew. Chem. Int. Ed. Engl. 1989, 28, 213. Binger, P.; Buch, H. M. Top. Curr. Chem. 1987, 135, 77. (g) Davies, H. M. L. Tetrahedron 1993, 49, 5203. (h) Hosomi, A.; Tominaga, Y. in Comprehensive Organic Synthesis; Trost, B. M., Fleming, I. Paquette, L. A., Eds.; Pergamon Press: New York, 1991; Vol 5, pp 593-615. (i) Boger, D. L.; Brotherton, C. E. J. Org. Chem. 1985, 50, 3425.
26. Alternatively, [6 + 1], [5 + 2], and [4 + 3] cycloadditions lead to 7-membered rings. For examples and lead references, see: (I) [6 + 1]: Ye, T.; McKervey, M. A. Chem. Rev. (Washington, D.C.) 1994, 94, 1091. [5 + 2]: (a) Sánchez, I. H.; Yáñez, R.; Enríquez, R.; Joseph-Nathan, P. J. Org. Chem. 1981, 46, 2818. (b) Sammes, P. G. Gazz. Chim. Ital. 1986, 116, 109. (c) Wender, P. A.; Lee. H. Y.; Wilhelm, R. S.; Williams, P. D. J. Am. Chem. Soc. 1989, 111, 8954. (d) Padwa, A.; Hornbuckel, S. F.; Fryxell, G. E.; Stull, P. D. J. Org. Chem. 1992, 57, 5747. (e) Wender, P. A.; Siggel, L.; Nuss, J. M. In Comprehensive Organic Synthesis; Trost, B. M., Fleming, I., Paquette, L. A., Eds.; Pergamon Press: New York, 1991; Vol 5, p 645-673. (f) Wender, P. A.; Takahashi, H.; Witulski, B. J. Am. Chem. Soc. 1995, 117, 4720. [4 + 3]: (a) Norori, R. Acc. Chem. Res 1979, 12, 61. (b) Hoffmann, H. M. R. Angew. Chem., Int. Ed. Engl. 1984, 23, 1. (c) Mann, J. Tetrahedron 1986, 421, 4611. (d) Harmata, M.; Elahmad, S. Tetrahedron Lett. 1993, 34, 789. (e) Giguere, R. J.; Tassely, S. M.; Rose, M. I.; Krishnamurthy, V. V. Tetrahedron Lett. 1990, 31, 4577. (f) Trost, B. M.; Schneider, S. Angew. Chem. Int. Ed. Engl. 1989, 28, 213. Binger, P.; Buch, H. M. Top. Curr. Chem. 1987, 135, 77. (g) Davies, H. M. L. Tetrahedron 1993, 49, 5203. (h) Hosomi, A.; Tominaga, Y. in Comprehensive Organic Synthesis; Trost, B. M., Fleming, I. Paquette, L. A., Eds.; Pergamon Press: New York, 1991; Vol 5, pp 593-615. (i) Boger, D. L.; Brotherton, C. E. J. Org. Chem. 1985, 50, 3425.
27. Alternatively, [6 + 1], [5 + 2], and [4 + 3] cycloadditions lead to 7-membered rings. For examples and lead references, see: (I) [6 + 1]: Ye, T.; McKervey, M. A. Chem. Rev. (Washington, D.C.) 1994, 94, 1091. [5 + 2]: (a) Sánchez, I. H.; Yáñez, R.; Enríquez, R.; Joseph-Nathan, P. J. Org. Chem. 1981, 46, 2818. (b) Sammes, P. G. Gazz. Chim. Ital. 1986, 116, 109. (c) Wender, P. A.; Lee. H. Y.; Wilhelm, R. S.; Williams, P. D. J. Am. Chem. Soc. 1989, 111, 8954. (d) Padwa, A.; Hornbuckel, S. F.; Fryxell, G. E.; Stull, P. D. J. Org. Chem. 1992, 57, 5747. (e) Wender, P. A.; Siggel, L.; Nuss, J. M. In Comprehensive Organic Synthesis; Trost, B. M., Fleming, I., Paquette, L. A., Eds.; Pergamon Press: New York, 1991; Vol 5, p 645-673. (f) Wender, P. A.; Takahashi, H.; Witulski, B. J. Am. Chem. Soc. 1995, 117, 4720. [4 + 3]: (a) Norori, R. Acc. Chem. Res 1979, 12, 61. (b) Hoffmann, H. M. R. Angew. Chem., Int. Ed. Engl. 1984, 23, 1. (c) Mann, J. Tetrahedron 1986, 421, 4611. (d) Harmata, M.; Elahmad, S. Tetrahedron Lett. 1993, 34, 789. (e) Giguere, R. J.; Tassely, S. M.; Rose, M. I.; Krishnamurthy, V. V. Tetrahedron Lett. 1990, 31, 4577. (f) Trost, B. M.; Schneider, S. Angew. Chem. Int. Ed. Engl. 1989, 28, 213. Binger, P.; Buch, H. M. Top. Curr. Chem. 1987, 135, 77. (g) Davies, H. M. L. Tetrahedron 1993, 49, 5203. (h) Hosomi, A.; Tominaga, Y. in Comprehensive Organic Synthesis; Trost, B. M., Fleming, I. Paquette, L. A., Eds.; Pergamon Press: New York, 1991; Vol 5, pp 593-615. (i) Boger, D. L.; Brotherton, C. E. J. Org. Chem. 1985, 50, 3425.
28. Alternatively, [6 + 1], [5 + 2], and [4 + 3] cycloadditions lead to 7-membered rings. For examples and lead references, see: (I) [6 + 1]: Ye, T.; McKervey, M. A. Chem. Rev. (Washington, D.C.) 1994, 94, 1091. [5 + 2]: (a) Sánchez, I. H.; Yáñez, R.; Enríquez, R.; Joseph-Nathan, P. J. Org. Chem. 1981, 46, 2818. (b) Sammes, P. G. Gazz. Chim. Ital. 1986, 116, 109. (c) Wender, P. A.; Lee. H. Y.; Wilhelm, R. S.; Williams, P. D. J. Am. Chem. Soc. 1989, 111, 8954. (d) Padwa, A.; Hornbuckel, S. F.; Fryxell, G. E.; Stull, P. D. J. Org. Chem. 1992, 57, 5747. (e) Wender, P. A.; Siggel, L.; Nuss, J. M. In Comprehensive Organic Synthesis; Trost, B. M., Fleming, I., Paquette, L. A., Eds.; Pergamon Press: New York, 1991; Vol 5, p 645-673. (f) Wender, P. A.; Takahashi, H.; Witulski, B. J. Am. Chem. Soc. 1995, 117, 4720. [4 + 3]: (a) Norori, R. Acc. Chem. Res 1979, 12, 61. (b) Hoffmann, H. M. R. Angew. Chem., Int. Ed. Engl. 1984, 23, 1. (c) Mann, J. Tetrahedron 1986, 421, 4611. (d) Harmata, M.; Elahmad, S. Tetrahedron Lett. 1993, 34, 789. (e) Giguere, R. J.; Tassely, S. M.; Rose, M. I.; Krishnamurthy, V. V. Tetrahedron Lett. 1990, 31, 4577. (f) Trost, B. M.; Schneider, S. Angew. Chem. Int. Ed. Engl. 1989, 28, 213. Binger, P.; Buch, H. M. Top. Curr. Chem. 1987, 135, 77. (g) Davies, H. M. L. Tetrahedron 1993, 49, 5203. (h) Hosomi, A.; Tominaga, Y. in Comprehensive Organic Synthesis; Trost, B. M., Fleming, I. Paquette, L. A., Eds.; Pergamon Press: New York, 1991; Vol 5, pp 593-615. (i) Boger, D. L.; Brotherton, C. E. J. Org. Chem. 1985, 50, 3425.
29. Alternatively, [6 + 1], [5 + 2], and [4 + 3] cycloadditions lead to 7-membered rings. For examples and lead references, see: (I) [6 + 1]: Ye, T.; McKervey, M. A. Chem. Rev. (Washington, D.C.) 1994, 94, 1091. [5 + 2]: (a) Sánchez, I. H.; Yáñez, R.; Enríquez, R.; Joseph-Nathan, P. J. Org. Chem. 1981, 46, 2818. (b) Sammes, P. G. Gazz. Chim. Ital. 1986, 116, 109. (c) Wender, P. A.; Lee. H. Y.; Wilhelm, R. S.; Williams, P. D. J. Am. Chem. Soc. 1989, 111, 8954. (d) Padwa, A.; Hornbuckel, S. F.; Fryxell, G. E.; Stull, P. D. J. Org. Chem. 1992, 57, 5747. (e) Wender, P. A.; Siggel, L.; Nuss, J. M. In Comprehensive Organic Synthesis; Trost, B. M., Fleming, I., Paquette, L. A., Eds.; Pergamon Press: New York, 1991; Vol 5, p 645-673. (f) Wender, P. A.; Takahashi, H.; Witulski, B. J. Am. Chem. Soc. 1995, 117, 4720. [4 + 3]: (a) Norori, R. Acc. Chem. Res 1979, 12, 61. (b) Hoffmann, H. M. R. Angew. Chem., Int. Ed. Engl. 1984, 23, 1. (c) Mann, J. Tetrahedron 1986, 421, 4611. (d) Harmata, M.; Elahmad, S. Tetrahedron Lett. 1993, 34, 789. (e) Giguere, R. J.; Tassely, S. M.; Rose, M. I.; Krishnamurthy, V. V. Tetrahedron Lett. 1990, 31, 4577. (f) Trost, B. M.; Schneider, S. Angew. Chem. Int. Ed. Engl. 1989, 28, 213. Binger, P.; Buch, H. M. Top. Curr. Chem. 1987, 135, 77. (g) Davies, H. M. L. Tetrahedron 1993, 49, 5203. (h) Hosomi, A.; Tominaga, Y. in Comprehensive Organic Synthesis; Trost, B. M., Fleming, I. Paquette, L. A., Eds.; Pergamon Press: New York, 1991; Vol 5, pp 593-615. (i) Boger, D. L.; Brotherton, C. E. J. Org. Chem. 1985, 50, 3425.
30. Alternatively, [6 + 1], [5 + 2], and [4 + 3] cycloadditions lead to 7-membered rings. For examples and lead references, see: (I) [6 + 1]: Ye, T.; McKervey, M. A. Chem. Rev. (Washington, D.C.) 1994, 94, 1091. [5 + 2]: (a) Sánchez, I. H.; Yáñez, R.; Enríquez, R.; Joseph-Nathan, P. J. Org. Chem. 1981, 46, 2818. (b) Sammes, P. G. Gazz. Chim. Ital. 1986, 116, 109. (c) Wender, P. A.; Lee. H. Y.; Wilhelm, R. S.; Williams, P. D. J. Am. Chem. Soc. 1989, 111, 8954. (d) Padwa, A.; Hornbuckel, S. F.; Fryxell, G. E.; Stull, P. D. J. Org. Chem. 1992, 57, 5747. (e) Wender, P. A.; Siggel, L.; Nuss, J. M. In Comprehensive Organic Synthesis; Trost, B. M., Fleming, I., Paquette, L. A., Eds.; Pergamon Press: New York, 1991; Vol 5, p 645-673. (f) Wender, P. A.; Takahashi, H.; Witulski, B. J. Am. Chem. Soc. 1995, 117, 4720. [4 + 3]: (a) Norori, R. Acc. Chem. Res 1979, 12, 61. (b) Hoffmann, H. M. R. Angew. Chem., Int. Ed. Engl. 1984, 23, 1. (c) Mann, J. Tetrahedron 1986, 421, 4611. (d) Harmata, M.; Elahmad, S. Tetrahedron Lett. 1993, 34, 789. (e) Giguere, R. J.; Tassely, S. M.; Rose, M. I.; Krishnamurthy, V. V. Tetrahedron Lett. 1990, 31, 4577. (f) Trost, B. M.; Schneider, S. Angew. Chem. Int. Ed. Engl. 1989, 28, 213. Binger, P.; Buch, H. M. Top. Curr. Chem. 1987, 135, 77. (g) Davies, H. M. L. Tetrahedron 1993, 49, 5203. (h) Hosomi, A.; Tominaga, Y. in Comprehensive Organic Synthesis; Trost, B. M., Fleming, I. Paquette, L. A., Eds.; Pergamon Press: New York, 1991; Vol 5, pp 593-615. (i) Boger, D. L.; Brotherton, C. E. J. Org. Chem. 1985, 50, 3425.
31. Alternatively, [6 + 1], [5 + 2], and [4 + 3] cycloadditions lead to 7-membered rings. For examples and lead references, see: (I) [6 + 1]: Ye, T.; McKervey, M. A. Chem. Rev. (Washington, D.C.) 1994, 94, 1091. [5 + 2]: (a) Sánchez, I. H.; Yáñez, R.; Enríquez, R.; Joseph-Nathan, P. J. Org. Chem. 1981, 46, 2818. (b) Sammes, P. G. Gazz. Chim. Ital. 1986, 116, 109. (c) Wender, P. A.; Lee. H. Y.; Wilhelm, R. S.; Williams, P. D. J. Am. Chem. Soc. 1989, 111, 8954. (d) Padwa, A.; Hornbuckel, S. F.; Fryxell, G. E.; Stull, P. D. J. Org. Chem. 1992, 57, 5747. (e) Wender, P. A.; Siggel, L.; Nuss, J. M. In Comprehensive Organic Synthesis; Trost, B. M., Fleming, I., Paquette, L. A., Eds.; Pergamon Press: New York, 1991; Vol 5, p 645-673. (f) Wender, P. A.; Takahashi, H.; Witulski, B. J. Am. Chem. Soc. 1995, 117, 4720. [4 + 3]: (a) Norori, R. Acc. Chem. Res 1979, 12, 61. (b) Hoffmann, H. M. R. Angew. Chem., Int. Ed. Engl. 1984, 23, 1. (c) Mann, J. Tetrahedron 1986, 421, 4611. (d) Harmata, M.; Elahmad, S. Tetrahedron Lett. 1993, 34, 789. (e) Giguere, R. J.; Tassely, S. M.; Rose, M. I.; Krishnamurthy, V. V. Tetrahedron Lett. 1990, 31, 4577. (f) Trost, B. M.; Schneider, S. Angew. Chem. Int. Ed. Engl. 1989, 28, 213. Binger, P.; Buch, H. M. Top. Curr. Chem. 1987, 135, 77. (g) Davies, H. M. L. Tetrahedron 1993, 49, 5203. (h) Hosomi, A.; Tominaga, Y. in Comprehensive Organic Synthesis; Trost, B. M., Fleming, I. Paquette, L. A., Eds.; Pergamon Press: New York, 1991; Vol 5, pp 593-615. (i) Boger, D. L.; Brotherton, C. E. J. Org. Chem. 1985, 50, 3425.
32. Alternatively, [6 + 1], [5 + 2], and [4 + 3] cycloadditions lead to 7-membered rings. For examples and lead references, see: (I) [6 + 1]: Ye, T.; McKervey, M. A. Chem. Rev. (Washington, D.C.) 1994, 94, 1091. [5 + 2]: (a) Sánchez, I. H.; Yáñez, R.; Enríquez, R.; Joseph-Nathan, P. J. Org. Chem. 1981, 46, 2818. (b) Sammes, P. G. Gazz. Chim. Ital. 1986, 116, 109. (c) Wender, P. A.; Lee. H. Y.; Wilhelm, R. S.; Williams, P. D. J. Am. Chem. Soc. 1989, 111, 8954. (d) Padwa, A.; Hornbuckel, S. F.; Fryxell, G. E.; Stull, P. D. J. Org. Chem. 1992, 57, 5747. (e) Wender, P. A.; Siggel, L.; Nuss, J. M. In Comprehensive Organic Synthesis; Trost, B. M., Fleming, I., Paquette, L. A., Eds.; Pergamon Press: New York, 1991; Vol 5, p 645-673. (f) Wender, P. A.; Takahashi, H.; Witulski, B. J. Am. Chem. Soc. 1995, 117, 4720. [4 + 3]: (a) Norori, R. Acc. Chem. Res 1979, 12, 61. (b) Hoffmann, H. M. R. Angew. Chem., Int. Ed. Engl. 1984, 23, 1. (c) Mann, J. Tetrahedron 1986, 421, 4611. (d) Harmata, M.; Elahmad, S. Tetrahedron Lett. 1993, 34, 789. (e) Giguere, R. J.; Tassely, S. M.; Rose, M. I.; Krishnamurthy, V. V. Tetrahedron Lett. 1990, 31, 4577. (f) Trost, B. M.; Schneider, S. Angew. Chem. Int. Ed. Engl. 1989, 28, 213. Binger, P.; Buch, H. M. Top. Curr. Chem. 1987, 135, 77. (g) Davies, H. M. L. Tetrahedron 1993, 49, 5203. (h) Hosomi, A.; Tominaga, Y. in Comprehensive Organic Synthesis; Trost, B. M., Fleming, I. Paquette, L. A., Eds.; Pergamon Press: New York, 1991; Vol 5, pp 593-615. (i) Boger, D. L.; Brotherton, C. E. J. Org. Chem. 1985, 50, 3425.
33. Alternatively, [6 + 1], [5 + 2], and [4 + 3] cycloadditions lead to 7-membered rings. For examples and lead references, see: (I) [6 + 1]: Ye, T.; McKervey, M. A. Chem. Rev. (Washington, D.C.) 1994, 94, 1091. [5 + 2]: (a) Sánchez, I. H.; Yáñez, R.; Enríquez, R.; Joseph-Nathan, P. J. Org. Chem. 1981, 46, 2818. (b) Sammes, P. G. Gazz. Chim. Ital. 1986, 116, 109. (c) Wender, P. A.; Lee. H. Y.; Wilhelm, R. S.; Williams, P. D. J. Am. Chem. Soc. 1989, 111, 8954. (d) Padwa, A.; Hornbuckel, S. F.; Fryxell, G. E.; Stull, P. D. J. Org. Chem. 1992, 57, 5747. (e) Wender, P. A.; Siggel, L.; Nuss, J. M. In Comprehensive Organic Synthesis; Trost, B. M., Fleming, I., Paquette, L. A., Eds.; Pergamon Press: New York, 1991; Vol 5, p 645-673. (f) Wender, P. A.; Takahashi, H.; Witulski, B. J. Am. Chem. Soc. 1995, 117, 4720. [4 + 3]: (a) Norori, R. Acc. Chem. Res 1979, 12, 61. (b) Hoffmann, H. M. R. Angew. Chem., Int. Ed. Engl. 1984, 23, 1. (c) Mann, J. Tetrahedron 1986, 421, 4611. (d) Harmata, M.; Elahmad, S. Tetrahedron Lett. 1993, 34, 789. (e) Giguere, R. J.; Tassely, S. M.; Rose, M. I.; Krishnamurthy, V. V. Tetrahedron Lett. 1990, 31, 4577. (f) Trost, B. M.; Schneider, S. Angew. Chem. Int. Ed. Engl. 1989, 28, 213. Binger, P.; Buch, H. M. Top. Curr. Chem. 1987, 135, 77. (g) Davies, H. M. L. Tetrahedron 1993, 49, 5203. (h) Hosomi, A.; Tominaga, Y. in Comprehensive Organic Synthesis; Trost, B. M., Fleming, I. Paquette, L. A., Eds.; Pergamon Press: New York, 1991; Vol 5, pp 593-615. (i) Boger, D. L.; Brotherton, C. E. J. Org. Chem. 1985, 50, 3425.
34. Alternatively, [6 + 1], [5 + 2], and [4 + 3] cycloadditions lead to 7-membered rings. For examples and lead references, see: (I) [6 + 1]: Ye, T.; McKervey, M. A. Chem. Rev. (Washington, D.C.) 1994, 94, 1091. [5 + 2]: (a) Sánchez, I. H.; Yáñez, R.; Enríquez, R.; Joseph-Nathan, P. J. Org. Chem. 1981, 46, 2818. (b) Sammes, P. G. Gazz. Chim. Ital. 1986, 116, 109. (c) Wender, P. A.; Lee. H. Y.; Wilhelm, R. S.; Williams, P. D. J. Am. Chem. Soc. 1989, 111, 8954. (d) Padwa, A.; Hornbuckel, S. F.; Fryxell, G. E.; Stull, P. D. J. Org. Chem. 1992, 57, 5747. (e) Wender, P. A.; Siggel, L.; Nuss, J. M. In Comprehensive Organic Synthesis; Trost, B. M., Fleming, I., Paquette, L. A., Eds.; Pergamon Press: New York, 1991; Vol 5, p 645-673. (f) Wender, P. A.; Takahashi, H.; Witulski, B. J. Am. Chem. Soc. 1995, 117, 4720. [4 + 3]: (a) Norori, R. Acc. Chem. Res 1979, 12, 61. (b) Hoffmann, H. M. R. Angew. Chem., Int. Ed. Engl. 1984, 23, 1. (c) Mann, J. Tetrahedron 1986, 421, 4611. (d) Harmata, M.; Elahmad, S. Tetrahedron Lett. 1993, 34, 789. (e) Giguere, R. J.; Tassely, S. M.; Rose, M. I.; Krishnamurthy, V. V. Tetrahedron Lett. 1990, 31, 4577. (f) Trost, B. M.; Schneider, S. Angew. Chem. Int. Ed. Engl. 1989, 28, 213. Binger, P.; Buch, H. M. Top. Curr. Chem. 1987, 135, 77. (g) Davies, H. M. L. Tetrahedron 1993, 49, 5203. (h) Hosomi, A.; Tominaga, Y. in Comprehensive Organic Synthesis; Trost, B. M., Fleming, I. Paquette, L. A., Eds.; Pergamon Press: New York, 1991; Vol 5, pp 593-615. (i) Boger, D. L.; Brotherton, C. E. J. Org. Chem. 1985, 50, 3425.
35. Alternatively, [6 + 1], [5 + 2], and [4 + 3] cycloadditions lead to 7-membered rings. For examples and lead references, see: (I) [6 + 1]: Ye, T.; McKervey, M. A. Chem. Rev. (Washington, D.C.) 1994, 94, 1091. [5 + 2]: (a) Sánchez, I. H.; Yáñez, R.; Enríquez, R.; Joseph-Nathan, P. J. Org. Chem. 1981, 46, 2818. (b) Sammes, P. G. Gazz. Chim. Ital. 1986, 116, 109. (c) Wender, P. A.; Lee. H. Y.; Wilhelm, R. S.; Williams, P. D. J. Am. Chem. Soc. 1989, 111, 8954. (d) Padwa, A.; Hornbuckel, S. F.; Fryxell, G. E.; Stull, P. D. J. Org. Chem. 1992, 57, 5747. (e) Wender, P. A.; Siggel, L.; Nuss, J. M. In Comprehensive Organic Synthesis; Trost, B. M., Fleming, I., Paquette, L. A., Eds.; Pergamon Press: New York, 1991; Vol 5, p 645-673. (f) Wender, P. A.; Takahashi, H.; Witulski, B. J. Am. Chem. Soc. 1995, 117, 4720. [4 + 3]: (a) Norori, R. Acc. Chem. Res 1979, 12, 61. (b) Hoffmann, H. M. R. Angew. Chem., Int. Ed. Engl. 1984, 23, 1. (c) Mann, J. Tetrahedron 1986, 421, 4611. (d) Harmata, M.; Elahmad, S. Tetrahedron Lett. 1993, 34, 789. (e) Giguere, R. J.; Tassely, S. M.; Rose, M. I.; Krishnamurthy, V. V. Tetrahedron Lett. 1990, 31, 4577. (f) Trost, B. M.; Schneider, S. Angew. Chem. Int. Ed. Engl. 1989, 28, 213. Binger, P.; Buch, H. M. Top. Curr. Chem. 1987, 135, 77. (g) Davies, H. M. L. Tetrahedron 1993, 49, 5203. (h) Hosomi, A.; Tominaga, Y. in Comprehensive Organic Synthesis; Trost, B. M., Fleming, I. Paquette, L. A., Eds.; Pergamon Press: New York, 1991; Vol 5, pp 593-615. (i) Boger, D. L.; Brotherton, C. E. J. Org. Chem. 1985, 50, 3425.
36. Alternatively, [6 + 1], [5 + 2], and [4 + 3] cycloadditions lead to 7-membered rings. For examples and lead references, see: (I) [6 + 1]: Ye, T.; McKervey, M. A. Chem. Rev. (Washington, D.C.) 1994, 94, 1091. [5 + 2]: (a) Sánchez, I. H.; Yáñez, R.; Enríquez, R.; Joseph-Nathan, P. J. Org. Chem. 1981, 46, 2818. (b) Sammes, P. G. Gazz. Chim. Ital. 1986, 116, 109. (c) Wender, P. A.; Lee. H. Y.; Wilhelm, R. S.; Williams, P. D. J. Am. Chem. Soc. 1989, 111, 8954. (d) Padwa, A.; Hornbuckel, S. F.; Fryxell, G. E.; Stull, P. D. J. Org. Chem. 1992, 57, 5747. (e) Wender, P. A.; Siggel, L.; Nuss, J. M. In Comprehensive Organic Synthesis; Trost, B. M., Fleming, I., Paquette, L. A., Eds.; Pergamon Press: New York, 1991; Vol 5, p 645-673. (f) Wender, P. A.; Takahashi, H.; Witulski, B. J. Am. Chem. Soc. 1995, 117, 4720. [4 + 3]: (a) Norori, R. Acc. Chem. Res 1979, 12, 61. (b) Hoffmann, H. M. R. Angew. Chem., Int. Ed. Engl. 1984, 23, 1. (c) Mann, J. Tetrahedron 1986, 421, 4611. (d) Harmata, M.; Elahmad, S. Tetrahedron Lett. 1993, 34, 789. (e) Giguere, R. J.; Tassely, S. M.; Rose, M. I.; Krishnamurthy, V. V. Tetrahedron Lett. 1990, 31, 4577. (f) Trost, B. M.; Schneider, S. Angew. Chem. Int. Ed. Engl. 1989, 28, 213. Binger, P.; Buch, H. M. Top. Curr. Chem. 1987, 135, 77. (g) Davies, H. M. L. Tetrahedron 1993, 49, 5203. (h) Hosomi, A.; Tominaga, Y. in Comprehensive Organic Synthesis; Trost, B. M., Fleming, I. Paquette, L. A., Eds.; Pergamon Press: New York, 1991; Vol 5, pp 593-615. (i) Boger, D. L.; Brotherton, C. E. J. Org. Chem. 1985, 50, 3425.
37. Alternatively, [6 + 1], [5 + 2], and [4 + 3] cycloadditions lead to 7-membered rings. For examples and lead references, see: (I) [6 + 1]: Ye, T.; McKervey, M. A. Chem. Rev. (Washington, D.C.) 1994, 94, 1091. [5 + 2]: (a) Sánchez, I. H.; Yáñez, R.; Enríquez, R.; Joseph-Nathan, P. J. Org. Chem. 1981, 46, 2818. (b) Sammes, P. G. Gazz. Chim. Ital. 1986, 116, 109. (c) Wender, P. A.; Lee. H. Y.; Wilhelm, R. S.; Williams, P. D. J. Am. Chem. Soc. 1989, 111, 8954. (d) Padwa, A.; Hornbuckel, S. F.; Fryxell, G. E.; Stull, P. D. J. Org. Chem. 1992, 57, 5747. (e) Wender, P. A.; Siggel, L.; Nuss, J. M. In Comprehensive Organic Synthesis; Trost, B. M., Fleming, I., Paquette, L. A., Eds.; Pergamon Press: New York, 1991; Vol 5, p 645-673. (f) Wender, P. A.; Takahashi, H.; Witulski, B. J. Am. Chem. Soc. 1995, 117, 4720. [4 + 3]: (a) Norori, R. Acc. Chem. Res 1979, 12, 61. (b) Hoffmann, H. M. R. Angew. Chem., Int. Ed. Engl. 1984, 23, 1. (c) Mann, J. Tetrahedron 1986, 421, 4611. (d) Harmata, M.; Elahmad, S. Tetrahedron Lett. 1993, 34, 789. (e) Giguere, R. J.; Tassely, S. M.; Rose, M. I.; Krishnamurthy, V. V. Tetrahedron Lett. 1990, 31, 4577. (f) Trost, B. M.; Schneider, S. Angew. Chem. Int. Ed. Engl. 1989, 28, 213. Binger, P.; Buch, H. M. Top. Curr. Chem. 1987, 135, 77. (g) Davies, H. M. L. Tetrahedron 1993, 49, 5203. (h) Hosomi, A.; Tominaga, Y. in Comprehensive Organic Synthesis; Trost, B. M., Fleming, I. Paquette, L. A., Eds.; Pergamon Press: New York, 1991; Vol 5, pp 593-615. (i) Boger, D. L.; Brotherton, C. E. J. Org. Chem. 1985, 50, 3425.
38. (a) Corey, E. J., Cheng, X.-M. The Logic of Chemical Synthesis, Wiley: New York, 1989.
39. (b) Ho, T.-L. Carbocyclic Construction in Terpenes Synthesis, VCH: New York, 1988.
40. (c) Heathcock, C. H.; Graham, S. L.; Pirrung, M. C. In The Total Synthesis of Natural Products: ApSimon, J. W., Ed.; Wiley: New York, 1983; Vol 5, p 323-333.
41. (a) de Jong, J. C.; Jansen, J. F.; Feringa, B. L. Tetrahedron Lett. 1990, 31, 3047-3050.
42. (b) Hoffmann, H.; Bolte, M.; Berger, B.; Hoppe, D. Tetrahedron Lett. 1993, 34, 6537-6540. Ando, K. Akadegawa, N. Takayama, H. J. Chem. Soc. Chem. Commun. 1991, 1765-1767.
43. (b) Hoffmann, H.; Bolte, M.; Berger, B.; Hoppe, D. Tetrahedron Lett. 1993, 34, 6537-6540. Ando, K. Akadegawa, N. Takayama, H. J. Chem. Soc. Chem. Commun. 1991, 1765-1767.
44. (c) Roush, W. R.; Ko, A. I., Gillis, H. J. Org. Chem. 1980, 45, 4264.
45. (d) Roush, W. R.; Gillis, H. R. J. Org. Chem. 1980, 45, 5, 4267.
46. (e) For other synthesis of functionalized indans involving cyclopentanone- cyclohexanone annulations or anionic Oxy-Cope rearrangements of bicyclo[2.2.1] systems, see: (i) Dahnke, K. R.; Paquette, L. A. J. Org. Chem. 1994, 59, 885-889. (i) Suri, S. C. Tetrahedron Lett. 1996, 37, 2335. (ii) Greene, A. E.; Coelho, F.; Barreiro, E. J.; Costa, P. R. J. Org. Chem. 1986, 51, 4250. (iii) Greene, A. E.; Serra, A.; Coelho, F.; Barreiro, E. J.; Costa, P. R. J. Org. Chem. 1987, 52, 1169. (iv) Piers, E.; Yeung, B. W. A. J. Org. Chem. 1984, 49, 4567. (v) Piers, E.; Yeung, B. W. A. Can. J. Chem. 1986, 64, 2475. (vi) Jung, M. E.; Hudspeth, J. P. J. Am. Chem. Soc., 1978, 100, 4309.
47. (e) For other synthesis of functionalized indans involving cyclopentanone- cyclohexanone annulations or anionic Oxy-Cope rearrangements of bicyclo[2.2.1] systems, see: (i) Dahnke, K. R.; Paquette, L. A. J. Org. Chem. 1994, 59, 885-889. (i) Suri, S. C. Tetrahedron Lett. 1996, 37, 2335. (ii) Greene, A. E.; Coelho, F.; Barreiro, E. J.; Costa, P. R. J. Org. Chem. 1986, 51, 4250. (iii) Greene, A. E.; Serra, A.; Coelho, F.; Barreiro, E. J.; Costa, P. R. J. Org. Chem. 1987, 52, 1169. (iv) Piers, E.; Yeung, B. W. A. J. Org. Chem. 1984, 49, 4567. (v) Piers, E.; Yeung, B. W. A. Can. J. Chem. 1986, 64, 2475. (vi) Jung, M. E.; Hudspeth, J. P. J. Am. Chem. Soc., 1978, 100, 4309.
48. (e) For other synthesis of functionalized indans involving cyclopentanone- cyclohexanone annulations or anionic Oxy-Cope rearrangements of bicyclo[2.2.1] systems, see: (i) Dahnke, K. R.; Paquette, L. A. J. Org. Chem. 1994, 59, 885-889. (i) Suri, S. C. Tetrahedron Lett. 1996, 37, 2335. (ii) Greene, A. E.; Coelho, F.; Barreiro, E. J.; Costa, P. R. J. Org. Chem. 1986, 51, 4250. (iii) Greene, A. E.; Serra, A.; Coelho, F.; Barreiro, E. J.; Costa, P. R. J. Org. Chem. 1987, 52, 1169. (iv) Piers, E.; Yeung, B. W. A. J. Org. Chem. 1984, 49, 4567. (v) Piers, E.; Yeung, B. W. A. Can. J. Chem. 1986, 64, 2475. (vi) Jung, M. E.; Hudspeth, J. P. J. Am. Chem. Soc., 1978, 100, 4309.
49. (e) For other synthesis of functionalized indans involving cyclopentanone- cyclohexanone annulations or anionic Oxy-Cope rearrangements of bicyclo[2.2.1] systems, see: (i) Dahnke, K. R.; Paquette, L. A. J. Org. Chem. 1994, 59, 885-889. (i) Suri, S. C. Tetrahedron Lett. 1996, 37, 2335. (ii) Greene, A. E.; Coelho, F.; Barreiro, E. J.; Costa, P. R. J. Org. Chem. 1986, 51, 4250. (iii) Greene, A. E.; Serra, A.; Coelho, F.; Barreiro, E. J.; Costa, P. R. J. Org. Chem. 1987, 52, 1169. (iv) Piers, E.; Yeung, B. W. A. J. Org. Chem. 1984, 49, 4567. (v) Piers, E.; Yeung, B. W. A. Can. J. Chem. 1986, 64, 2475. (vi) Jung, M. E.; Hudspeth, J. P. J. Am. Chem. Soc., 1978, 100, 4309.
50. (e) For other synthesis of functionalized indans involving cyclopentanone- cyclohexanone annulations or anionic Oxy-Cope rearrangements of bicyclo[2.2.1] systems, see: (i) Dahnke, K. R.; Paquette, L. A. J. Org. Chem. 1994, 59, 885-889. (i) Suri, S. C. Tetrahedron Lett. 1996, 37, 2335. (ii) Greene, A. E.; Coelho, F.; Barreiro, E. J.; Costa, P. R. J. Org. Chem. 1986, 51, 4250. (iii) Greene, A. E.; Serra, A.; Coelho, F.; Barreiro, E. J.; Costa, P. R. J. Org. Chem. 1987, 52, 1169. (iv) Piers, E.; Yeung, B. W. A. J. Org. Chem. 1984, 49, 4567. (v) Piers, E.; Yeung, B. W. A. Can. J. Chem. 1986, 64, 2475. (vi) Jung, M. E.; Hudspeth, J. P. J. Am. Chem. Soc., 1978, 100, 4309.
51. (e) For other synthesis of functionalized indans involving cyclopentanone- cyclohexanone annulations or anionic Oxy-Cope rearrangements of bicyclo[2.2.1] systems, see: (i) Dahnke, K. R.; Paquette, L. A. J. Org. Chem. 1994, 59, 885-889. (i) Suri, S. C. Tetrahedron Lett. 1996, 37, 2335. (ii) Greene, A. E.; Coelho, F.; Barreiro, E. J.; Costa, P. R. J. Org. Chem. 1986, 51, 4250. (iii) Greene, A. E.; Serra, A.; Coelho, F.; Barreiro, E. J.; Costa, P. R. J. Org. Chem. 1987, 52, 1169. (iv) Piers, E.; Yeung, B. W. A. J. Org. Chem. 1984, 49, 4567. (v) Piers, E.; Yeung, B. W. A. Can. J. Chem. 1986, 64, 2475. (vi) Jung, M. E.; Hudspeth, J. P. J. Am. Chem. Soc., 1978, 100, 4309.
52. (e) For other synthesis of functionalized indans involving cyclopentanone- cyclohexanone annulations or anionic Oxy-Cope rearrangements of bicyclo[2.2.1] systems, see: (i) Dahnke, K. R.; Paquette, L. A. J. Org. Chem. 1994, 59, 885-889. (i) Suri, S. C. Tetrahedron Lett. 1996, 37, 2335. (ii) Greene, A. E.; Coelho, F.; Barreiro, E. J.; Costa, P. R. J. Org. Chem. 1986, 51, 4250. (iii) Greene, A. E.; Serra, A.; Coelho, F.; Barreiro, E. J.; Costa, P. R. J. Org. Chem. 1987, 52, 1169. (iv) Piers, E.; Yeung, B. W. A. J. Org. Chem. 1984, 49, 4567. (v) Piers, E.; Yeung, B. W. A. Can. J. Chem. 1986, 64, 2475. (vi) Jung, M. E.; Hudspeth, J. P. J. Am. Chem. Soc., 1978, 100, 4309.
53. For a preliminary account of some of this work, see: Hong, B.- C.; Sun, S.-S. Tetrahedron Lett. 1996, 37, 659.
54. Trost, B. M.; Seoane, P. R. J. Am. Chem. Soc. 1987, 109, 615.
55. Prior to this work, several cycloadditions of diphenylnitrileimine or nitrile oxide with tropone were reported. However, these reactions were low yielding and the [6 + 3] adducts were the minor products. See: (a) Bonadeo, M.; De Micheli, C.; Gandolfi, R. J. Chem. Soc., Perkin Trans. 1 1977, 939. (b) Houk, K. N.; Watts, C. R. Tetrahedron Lett. 1970, 4025. (c) De Micheli, C.; Gandolfi, R.; Gruüanger, P.; Tetrahedron, 1974, 30, 3765. (d) Mukherjee, D.; Watts, C. R.; Houk, K. N. J. Org. Chem. 1978, 43, 817.
56. Prior to this work, several cycloadditions of diphenylnitrileimine or nitrile oxide with tropone were reported. However, these reactions were low yielding and the [6 + 3] adducts were the minor products. See: (a) Bonadeo, M.; De Micheli, C.; Gandolfi, R. J. Chem. Soc., Perkin Trans. 1 1977, 939. (b) Houk, K. N.; Watts, C. R. Tetrahedron Lett. 1970, 4025. (c) De Micheli, C.; Gandolfi, R.; Gruüanger, P.; Tetrahedron, 1974, 30, 3765. (d) Mukherjee, D.; Watts, C. R.; Houk, K. N. J. Org. Chem. 1978, 43, 817.
57. Prior to this work, several cycloadditions of diphenylnitrileimine or nitrile oxide with tropone were reported. However, these reactions were low yielding and the [6 + 3] adducts were the minor products. See: (a) Bonadeo, M.; De Micheli, C.; Gandolfi, R. J. Chem. Soc., Perkin Trans. 1 1977, 939. (b) Houk, K. N.; Watts, C. R. Tetrahedron Lett. 1970, 4025. (c) De Micheli, C.; Gandolfi, R.; Gruüanger, P.; Tetrahedron, 1974, 30, 3765. (d) Mukherjee, D.; Watts, C. R.; Houk, K. N. J. Org. Chem. 1978, 43, 817.
58. Prior to this work, several cycloadditions of diphenylnitrileimine or nitrile oxide with tropone were reported. However, these reactions were low yielding and the [6 + 3] adducts were the minor products. See: (a) Bonadeo, M.; De Micheli, C.; Gandolfi, R. J. Chem. Soc., Perkin Trans. 1 1977, 939. (b) Houk, K. N.; Watts, C. R. Tetrahedron Lett. 1970, 4025. (c) De Micheli, C.; Gandolfi, R.; Gruüanger, P.; Tetrahedron, 1974, 30, 3765. (d) Mukherjee, D.; Watts, C. R.; Houk, K. N. J. Org. Chem. 1978, 43, 817.
59. 9) with tropones afford the corresponding [8 + 3] cycloaddition adduct. See: Ishizu, T.; Mori, M.; Kanematsu, K. J. Org. Chem. 1981, 46, 526.
60. Chaffee, K.; Morcos, H.; Sheridan, J. B. Tetrahedron Lett. 1995, 36, 1577.
61. The 1,3-dipolar cycloaddition of diazomethane, azirine, nitrile oxide, or nitropyridyl betaine with fulvenes is known; however, these reactions give low yields. See: (a) Houk, K. N.; Luskus, L. J. Tetrahedron Lett. 1970, 4029. (b) Padwa, A.; Nobs, F. Tetrahedron Lett. 1978, 93. (c) Dennis, N.; Ibrahim, B.; Katritzky, A. R. J. Chem. Soc., Perkin Trans 1 1976, 2307. (d) Caramella, P.; Frattini, P.; Grünanger, P. Tetrahedron Lett. 1971, 3817.
62. The 1,3-dipolar cycloaddition of diazomethane, azirine, nitrile oxide, or nitropyridyl betaine with fulvenes is known; however, these reactions give low yields. See: (a) Houk, K. N.; Luskus, L. J. Tetrahedron Lett. 1970, 4029. (b) Padwa, A.; Nobs, F. Tetrahedron Lett. 1978, 93. (c) Dennis, N.; Ibrahim, B.; Katritzky, A. R. J. Chem. Soc., Perkin Trans 1 1976, 2307. (d) Caramella, P.; Frattini, P.; Grünanger, P. Tetrahedron Lett. 1971, 3817.
63. The 1,3-dipolar cycloaddition of diazomethane, azirine, nitrile oxide, or nitropyridyl betaine with fulvenes is known; however, these reactions give low yields. See: (a) Houk, K. N.; Luskus, L. J. Tetrahedron Lett. 1970, 4029. (b) Padwa, A.; Nobs, F. Tetrahedron Lett. 1978, 93. (c) Dennis, N.; Ibrahim, B.; Katritzky, A. R. J. Chem. Soc., Perkin Trans 1 1976, 2307. (d) Caramella, P.; Frattini, P.; Grünanger, P. Tetrahedron Lett. 1971, 3817.
64. The 1,3-dipolar cycloaddition of diazomethane, azirine, nitrile oxide, or nitropyridyl betaine with fulvenes is known; however, these reactions give low yields. See: (a) Houk, K. N.; Luskus, L. J. Tetrahedron Lett. 1970, 4029. (b) Padwa, A.; Nobs, F. Tetrahedron Lett. 1978, 93. (c) Dennis, N.; Ibrahim, B.; Katritzky, A. R. J. Chem. Soc., Perkin Trans 1 1976, 2307. (d) Caramella, P.; Frattini, P.; Grünanger, P. Tetrahedron Lett. 1971, 3817.
65. For reviews on the synthetic utility of oxyallyl cations, see: (a) Mann, J. Tetrahedron 1986, 42, 4611. (b) Hoffmann, H. M. R. Angew. Chem., Int. Engl. 1973, 12, 819.
66. For reviews on the synthetic utility of oxyallyl cations, see: (a) Mann, J. Tetrahedron 1986, 42, 4611. (b) Hoffmann, H. M. R. Angew. Chem., Int. Engl. 1973, 12, 819.
67. A variety of [4 + 3] cycloadditions have been employed in the total synthesis of natural products. See: (a) Kashman, Y.; Rudi, A. Tetrahedron 1974, 30, 109. (b) Rawson, D. I.; Carpenter, B. K.; Hoffmann, H. R. J. Am. Chem. Soc. 1979, 101, 1786. (c) Takaya, H.; Makino, S.; Hayakawa, Y.; Noyori, R. J. Am. Chem. Soc. 1978, 100, 1765. (d) Noyori, R.; Hayakawa, Y.; Takaya, H.; Murai, S.; Kobayashi, R.; Sonoda, N. J. Am. Chem. Soc. 1978, 100, 1759.
68. A variety of [4 + 3] cycloadditions have been employed in the total synthesis of natural products. See: (a) Kashman, Y.; Rudi, A. Tetrahedron 1974, 30, 109. (b) Rawson, D. I.; Carpenter, B. K.; Hoffmann, H. R. J. Am. Chem. Soc. 1979, 101, 1786. (c) Takaya, H.; Makino, S.; Hayakawa, Y.; Noyori, R. J. Am. Chem. Soc. 1978, 100, 1765. (d) Noyori, R.; Hayakawa, Y.; Takaya, H.; Murai, S.; Kobayashi, R.; Sonoda, N. J. Am. Chem. Soc. 1978, 100, 1759.
69. A variety of [4 + 3] cycloadditions have been employed in the total synthesis of natural products. See: (a) Kashman, Y.; Rudi, A. Tetrahedron 1974, 30, 109. (b) Rawson, D. I.; Carpenter, B. K.; Hoffmann, H. R. J. Am. Chem. Soc. 1979, 101, 1786. (c) Takaya, H.; Makino, S.; Hayakawa, Y.; Noyori, R. J. Am. Chem. Soc. 1978, 100, 1765. (d) Noyori, R.; Hayakawa, Y.; Takaya, H.; Murai, S.; Kobayashi, R.; Sonoda, N. J. Am. Chem. Soc. 1978, 100, 1759.
70. A variety of [4 + 3] cycloadditions have been employed in the total synthesis of natural products. See: (a) Kashman, Y.; Rudi, A. Tetrahedron 1974, 30, 109. (b) Rawson, D. I.; Carpenter, B. K.; Hoffmann, H. R. J. Am. Chem. Soc. 1979, 101, 1786. (c) Takaya, H.; Makino, S.; Hayakawa, Y.; Noyori, R. J. Am. Chem. Soc. 1978, 100, 1765. (d) Noyori, R.; Hayakawa, Y.; Takaya, H.; Murai, S.; Kobayashi, R.; Sonoda, N. J. Am. Chem. Soc. 1978, 100, 1759.
71. Ishizu, T.; Mori, M.; Kanematsu, K. J. Org. Chem. 1981, 46, 526-531.
72. The dipole moment of fulvenes can be enhanced by increasing the electron density on C-6. For previous preparations of this fulvene, see: (a) Olsson, T.; Wennerström, O. Acta Chem. Scand. B, 1978, 32, 293. (b) Bönzli, P.; Otter, A.; Neuenschwander, M.; Huber, H.; Kellerhals, H. P. Helv. Chem. Acta 1986, 69, 1052.
73. The dipole moment of fulvenes can be enhanced by increasing the electron density on C-6. For previous preparations of this fulvene, see: (a) Olsson, T.; Wennerström, O. Acta Chem. Scand. B, 1978, 32, 293. (b) Bönzli, P.; Otter, A.; Neuenschwander, M.; Huber, H.; Kellerhals, H. P. Helv. Chem. Acta 1986, 69, 1052.
74. For a preliminary account of the [6 + 4] cycloadditions of fulvene 1 and α-pyrones, see: Hong, B.-C.; Sun, S.-S. Chem. Commun. 1996, 937.
75. 3I gas cost $713 (Aldrich Chemical Co., 1996-1997).
76. No detailed procedure was reported for the preparation of fulvene 1 in ref 17b. However, the reaction is quite complicated and gives a lower overall yield than our methodology (vide infra).
77. The fulvene 1 was prepared on a 100 g scale by reaction of cyclopentadiene with KOH and 2-chloroethyl chloroformate as described: Hong, B.-C.; Hong, J.-S., Synth. Comm. 1997, in press.
78. Due to 1,5-H shifts, these compounds tend to isomerize further to unseparable mixtures of double bond isomers. Direct hydrolysis of these adducts, however, affords stable indenes (vide infra).
79. Hayakawa, Y.; Yokoyama, K.; Noyori, R. J. Am. Chem. Soc. 1978, 100, 0, 1971.
80. Some of the protons in Figure 1 have been omitted for clarity.
81. For a similar mechanic study of the regioselectivity in the [3 + 2] cycloaddition of 2-oxyallyl cation and alkenes, see: Noyori, R.; Shimizu, F.; Fukuta, K.; Takaya, H.; Hayakawa, Y. J. Am. Chem. Soc. 1977, 99, 5196.
82. Gompper, R.; Kutter, E. Chem. Ber. 1965, 98, 2825.
83. For a detailed mechanic study on this type of electrophilic addition of 2-oxyallyl cation to dienes, see: Hoffmann, H. M. R. Angew. Chem. 1984, 23, 1-88.