Synthesis of tricyclic β-methylene spiro lactones related to bakkenolides by successive radical cyclization-high pressure Diels-Alder reactions

Journal of Organic Chemistry

Volumn 61, Issue 11, 1996, Pages 3806-3814

  Back, Thomas G ^a   Gladstone, Patricia L ^a   Parvez, Masood ^a  

^a UNIVERSITY OF CALGARY   (Canada)

Author keywords

[No Author keywords available]

Indexed keywords

EID: 0000281787     PISSN: 00223263     EISSN: None     Source Type: Journal    
DOI: 10.1021/jo960111+     Document Type: Article

References (81)

1. (a) For a review, see: Fischer, N. H.; Olivier, E. J.; Fischer, H. D. In Progress in the Chemistry of Organic Natural Products; Herz, W.; Grisebach, H.; Kirby, G. W., Eds.; Springer-Verlag: Wien, 1979; Volume 38, pp 257-264.
2. (b) Abe, N.; Onoda, R.; Shirahata, K.; Kato, T.; Woods, M.C.; Kitahara, Y. Tetrahedron Lett. 1968, 369.
3. (c) Harmatha, J.; Samek, Z.; Synácková, M.; Novotný, L.; Herout, V.; Šorm, F.; Collect. Czech. Chem. Commun. 1976, 41, 2047.
4. (a) Jamieson, G. R.; Reid, E. H.; Turner, B. P.; Jamieson, A. T. Phytochem. 1976, 15, 1713.
5. (b) Kano, K.; Hayashi, K.; Mitsuhashi, H. Chem. Pharm. Bull. 1982, 30, 1198.
6. Nawrot, J.; Bloszyk, E.; Harmatha, J.; Novotný, L.; Drozdz, B. Acta Entomol. Bohemoslov. 1986, 83, 327; via Chem. Abstr. 1987, 106, 48926r.
7. Nawrot, J.; Bloszyk, E.; Harmatha, J.; Novotný, L.; Drozdz, B. Acta Entomol. Bohemoslov. 1986, 83, 327; via Chem. Abstr. 1987, 106, 48926r.
8. Bakkenolide-A: (a) Srikrishna, A.; Reddy, T. J.; Nagaraju, S.; Sattigeri, J. A. Tetrahedron Lett. 1994, 35, 7841. (b) Greene, A. E.; Coelho, F.; Deprés, J.-P.; Brocksom, T. J. Tetrahedron Lett. 1988, 29, 5661. (c) Greene, A. E.; Deprés, J.-P.; Coelho, F.; Brocksom, T. J. J. Org. Chem. 1985, 50, 3943. (d) Evans, D. A.; Sims, C. L.; Andrews, G. C. J. Am. Chem. Soc. 1977, 99, 5453. (e) Hayashi, K.; Nakamura, H.; Mitsuhashi, H. Chem. Pharm. Bull. 1973, 21, 2806. Homogynolide-A: (f) Mori, K.; Matsushima, Y. Synthesis 1995, 845. (g) Hartmann, B.; Kanazawa, A. M.; Deprés, J.-P.; Greene, A. E. Tetrahedron Lett. 1993, 34, 3875. (h) Hartmann, B.; Kanazawa, A. M.; Deprés, J.-P.; Greene, A. E. Tetrahedron Lett. 1991, 32, 767. Homogynolide-B: (i) Srikrishna, A.; Nagaraju, S.; Venkateswarlu, S. Tetrahedron Lett. 1994, 35, 429. (j) Coelho, F.; Deprés, J.-P.; Brocksom, T. J.; Greene, A. E. Tetrahedron Lett. 1989, 30, 565.
9. Bakkenolide-A: (a) Srikrishna, A.; Reddy, T. J.; Nagaraju, S.; Sattigeri, J. A. Tetrahedron Lett. 1994, 35, 7841. (b) Greene, A. E.; Coelho, F.; Deprés, J.-P.; Brocksom, T. J. Tetrahedron Lett. 1988, 29, 5661. (c) Greene, A. E.; Deprés, J.-P.; Coelho, F.; Brocksom, T. J. J. Org. Chem. 1985, 50, 3943. (d) Evans, D. A.; Sims, C. L.; Andrews, G. C. J. Am. Chem. Soc. 1977, 99, 5453. (e) Hayashi, K.; Nakamura, H.; Mitsuhashi, H. Chem. Pharm. Bull. 1973, 21, 2806. Homogynolide-A: (f) Mori, K.; Matsushima, Y. Synthesis 1995, 845. (g) Hartmann, B.; Kanazawa, A. M.; Deprés, J.-P.; Greene, A. E. Tetrahedron Lett. 1993, 34, 3875. (h) Hartmann, B.; Kanazawa, A. M.; Deprés, J.-P.; Greene, A. E. Tetrahedron Lett. 1991, 32, 767. Homogynolide-B: (i) Srikrishna, A.; Nagaraju, S.; Venkateswarlu, S. Tetrahedron Lett. 1994, 35, 429. (j) Coelho, F.; Deprés, J.-P.; Brocksom, T. J.; Greene, A. E. Tetrahedron Lett. 1989, 30, 565.
10. Bakkenolide-A: (a) Srikrishna, A.; Reddy, T. J.; Nagaraju, S.; Sattigeri, J. A. Tetrahedron Lett. 1994, 35, 7841. (b) Greene, A. E.; Coelho, F.; Deprés, J.-P.; Brocksom, T. J. Tetrahedron Lett. 1988, 29, 5661. (c) Greene, A. E.; Deprés, J.-P.; Coelho, F.; Brocksom, T. J. J. Org. Chem. 1985, 50, 3943. (d) Evans, D. A.; Sims, C. L.; Andrews, G. C. J. Am. Chem. Soc. 1977, 99, 5453. (e) Hayashi, K.; Nakamura, H.; Mitsuhashi, H. Chem. Pharm. Bull. 1973, 21, 2806. Homogynolide-A: (f) Mori, K.; Matsushima, Y. Synthesis 1995, 845. (g) Hartmann, B.; Kanazawa, A. M.; Deprés, J.-P.; Greene, A. E. Tetrahedron Lett. 1993, 34, 3875. (h) Hartmann, B.; Kanazawa, A. M.; Deprés, J.-P.; Greene, A. E. Tetrahedron Lett. 1991, 32, 767. Homogynolide-B: (i) Srikrishna, A.; Nagaraju, S.; Venkateswarlu, S. Tetrahedron Lett. 1994, 35, 429. (j) Coelho, F.; Deprés, J.-P.; Brocksom, T. J.; Greene, A. E. Tetrahedron Lett. 1989, 30, 565.
11. Bakkenolide-A: (a) Srikrishna, A.; Reddy, T. J.; Nagaraju, S.; Sattigeri, J. A. Tetrahedron Lett. 1994, 35, 7841. (b) Greene, A. E.; Coelho, F.; Deprés, J.-P.; Brocksom, T. J. Tetrahedron Lett. 1988, 29, 5661. (c) Greene, A. E.; Deprés, J.-P.; Coelho, F.; Brocksom, T. J. J. Org. Chem. 1985, 50, 3943. (d) Evans, D. A.; Sims, C. L.; Andrews, G. C. J. Am. Chem. Soc. 1977, 99, 5453. (e) Hayashi, K.; Nakamura, H.; Mitsuhashi, H. Chem. Pharm. Bull. 1973, 21, 2806. Homogynolide-A: (f) Mori, K.; Matsushima, Y. Synthesis 1995, 845. (g) Hartmann, B.; Kanazawa, A. M.; Deprés, J.-P.; Greene, A. E. Tetrahedron Lett. 1993, 34, 3875. (h) Hartmann, B.; Kanazawa, A. M.; Deprés, J.-P.; Greene, A. E. Tetrahedron Lett. 1991, 32, 767. Homogynolide-B: (i) Srikrishna, A.; Nagaraju, S.; Venkateswarlu, S. Tetrahedron Lett. 1994, 35, 429. (j) Coelho, F.; Deprés, J.-P.; Brocksom, T. J.; Greene, A. E. Tetrahedron Lett. 1989, 30, 565.
12. Bakkenolide-A: (a) Srikrishna, A.; Reddy, T. J.; Nagaraju, S.; Sattigeri, J. A. Tetrahedron Lett. 1994, 35, 7841. (b) Greene, A. E.; Coelho, F.; Deprés, J.-P.; Brocksom, T. J. Tetrahedron Lett. 1988, 29, 5661. (c) Greene, A. E.; Deprés, J.-P.; Coelho, F.; Brocksom, T. J. J. Org. Chem. 1985, 50, 3943. (d) Evans, D. A.; Sims, C. L.; Andrews, G. C. J. Am. Chem. Soc. 1977, 99, 5453. (e) Hayashi, K.; Nakamura, H.; Mitsuhashi, H. Chem. Pharm. Bull. 1973, 21, 2806. Homogynolide-A: (f) Mori, K.; Matsushima, Y. Synthesis 1995, 845. (g) Hartmann, B.; Kanazawa, A. M.; Deprés, J.-P.; Greene, A. E. Tetrahedron Lett. 1993, 34, 3875. (h) Hartmann, B.; Kanazawa, A. M.; Deprés, J.-P.; Greene, A. E. Tetrahedron Lett. 1991, 32, 767. Homogynolide-B: (i) Srikrishna, A.; Nagaraju, S.; Venkateswarlu, S. Tetrahedron Lett. 1994, 35, 429. (j) Coelho, F.; Deprés, J.-P.; Brocksom, T. J.; Greene, A. E. Tetrahedron Lett. 1989, 30, 565.
13. Bakkenolide-A: (a) Srikrishna, A.; Reddy, T. J.; Nagaraju, S.; Sattigeri, J. A. Tetrahedron Lett. 1994, 35, 7841. (b) Greene, A. E.; Coelho, F.; Deprés, J.-P.; Brocksom, T. J. Tetrahedron Lett. 1988, 29, 5661. (c) Greene, A. E.; Deprés, J.-P.; Coelho, F.; Brocksom, T. J. J. Org. Chem. 1985, 50, 3943. (d) Evans, D. A.; Sims, C. L.; Andrews, G. C. J. Am. Chem. Soc. 1977, 99, 5453. (e) Hayashi, K.; Nakamura, H.; Mitsuhashi, H. Chem. Pharm. Bull. 1973, 21, 2806. Homogynolide-A: (f) Mori, K.; Matsushima, Y. Synthesis 1995, 845. (g) Hartmann, B.; Kanazawa, A. M.; Deprés, J.-P.; Greene, A. E. Tetrahedron Lett. 1993, 34, 3875. (h) Hartmann, B.; Kanazawa, A. M.; Deprés, J.-P.; Greene, A. E. Tetrahedron Lett. 1991, 32, 767. Homogynolide-B: (i) Srikrishna, A.; Nagaraju, S.; Venkateswarlu, S. Tetrahedron Lett. 1994, 35, 429. (j) Coelho, F.; Deprés, J.-P.; Brocksom, T. J.; Greene, A. E. Tetrahedron Lett. 1989, 30, 565.
14. Bakkenolide-A: (a) Srikrishna, A.; Reddy, T. J.; Nagaraju, S.; Sattigeri, J. A. Tetrahedron Lett. 1994, 35, 7841. (b) Greene, A. E.; Coelho, F.; Deprés, J.-P.; Brocksom, T. J. Tetrahedron Lett. 1988, 29, 5661. (c) Greene, A. E.; Deprés, J.-P.; Coelho, F.; Brocksom, T. J. J. Org. Chem. 1985, 50, 3943. (d) Evans, D. A.; Sims, C. L.; Andrews, G. C. J. Am. Chem. Soc. 1977, 99, 5453. (e) Hayashi, K.; Nakamura, H.; Mitsuhashi, H. Chem. Pharm. Bull. 1973, 21, 2806. Homogynolide-A: (f) Mori, K.; Matsushima, Y. Synthesis 1995, 845. (g) Hartmann, B.; Kanazawa, A. M.; Deprés, J.-P.; Greene, A. E. Tetrahedron Lett. 1993, 34, 3875. (h) Hartmann, B.; Kanazawa, A. M.; Deprés, J.-P.; Greene, A. E. Tetrahedron Lett. 1991, 32, 767. Homogynolide-B: (i) Srikrishna, A.; Nagaraju, S.; Venkateswarlu, S. Tetrahedron Lett. 1994, 35, 429. (j) Coelho, F.; Deprés, J.-P.; Brocksom, T. J.; Greene, A. E. Tetrahedron Lett. 1989, 30, 565.
15. Bakkenolide-A: (a) Srikrishna, A.; Reddy, T. J.; Nagaraju, S.; Sattigeri, J. A. Tetrahedron Lett. 1994, 35, 7841. (b) Greene, A. E.; Coelho, F.; Deprés, J.-P.; Brocksom, T. J. Tetrahedron Lett. 1988, 29, 5661. (c) Greene, A. E.; Deprés, J.-P.; Coelho, F.; Brocksom, T. J. J. Org. Chem. 1985, 50, 3943. (d) Evans, D. A.; Sims, C. L.; Andrews, G. C. J. Am. Chem. Soc. 1977, 99, 5453. (e) Hayashi, K.; Nakamura, H.; Mitsuhashi, H. Chem. Pharm. Bull. 1973, 21, 2806. Homogynolide-A: (f) Mori, K.; Matsushima, Y. Synthesis 1995, 845. (g) Hartmann, B.; Kanazawa, A. M.; Deprés, J.-P.; Greene, A. E. Tetrahedron Lett. 1993, 34, 3875. (h) Hartmann, B.; Kanazawa, A. M.; Deprés, J.-P.; Greene, A. E. Tetrahedron Lett. 1991, 32, 767. Homogynolide-B: (i) Srikrishna, A.; Nagaraju, S.; Venkateswarlu, S. Tetrahedron Lett. 1994, 35, 429. (j) Coelho, F.; Deprés, J.-P.; Brocksom, T. J.; Greene, A. E. Tetrahedron Lett. 1989, 30, 565.
16. Bakkenolide-A: (a) Srikrishna, A.; Reddy, T. J.; Nagaraju, S.; Sattigeri, J. A. Tetrahedron Lett. 1994, 35, 7841. (b) Greene, A. E.; Coelho, F.; Deprés, J.-P.; Brocksom, T. J. Tetrahedron Lett. 1988, 29, 5661. (c) Greene, A. E.; Deprés, J.-P.; Coelho, F.; Brocksom, T. J. J. Org. Chem. 1985, 50, 3943. (d) Evans, D. A.; Sims, C. L.; Andrews, G. C. J. Am. Chem. Soc. 1977, 99, 5453. (e) Hayashi, K.; Nakamura, H.; Mitsuhashi, H. Chem. Pharm. Bull. 1973, 21, 2806. Homogynolide-A: (f) Mori, K.; Matsushima, Y. Synthesis 1995, 845. (g) Hartmann, B.; Kanazawa, A. M.; Deprés, J.-P.; Greene, A. E. Tetrahedron Lett. 1993, 34, 3875. (h) Hartmann, B.; Kanazawa, A. M.; Deprés, J.-P.; Greene, A. E. Tetrahedron Lett. 1991, 32, 767. Homogynolide-B: (i) Srikrishna, A.; Nagaraju, S.; Venkateswarlu, S. Tetrahedron Lett. 1994, 35, 429. (j) Coelho, F.; Deprés, J.-P.; Brocksom, T. J.; Greene, A. E. Tetrahedron Lett. 1989, 30, 565.
17. Bakkenolide-A: (a) Srikrishna, A.; Reddy, T. J.; Nagaraju, S.; Sattigeri, J. A. Tetrahedron Lett. 1994, 35, 7841. (b) Greene, A. E.; Coelho, F.; Deprés, J.-P.; Brocksom, T. J. Tetrahedron Lett. 1988, 29, 5661. (c) Greene, A. E.; Deprés, J.-P.; Coelho, F.; Brocksom, T. J. J. Org. Chem. 1985, 50, 3943. (d) Evans, D. A.; Sims, C. L.; Andrews, G. C. J. Am. Chem. Soc. 1977, 99, 5453. (e) Hayashi, K.; Nakamura, H.; Mitsuhashi, H. Chem. Pharm. Bull. 1973, 21, 2806. Homogynolide-A: (f) Mori, K.; Matsushima, Y. Synthesis 1995, 845. (g) Hartmann, B.; Kanazawa, A. M.; Deprés, J.-P.; Greene, A. E. Tetrahedron Lett. 1993, 34, 3875. (h) Hartmann, B.; Kanazawa, A. M.; Deprés, J.-P.; Greene, A. E. Tetrahedron Lett. 1991, 32, 767. Homogynolide-B: (i) Srikrishna, A.; Nagaraju, S.; Venkateswarlu, S. Tetrahedron Lett. 1994, 35, 429. (j) Coelho, F.; Deprés, J.-P.; Brocksom, T. J.; Greene, A. E. Tetrahedron Lett. 1989, 30, 565.
18. (a) Srikrishna, A.; Viswajanani, R.; Sattigeri, J. A. J. Chem. Soc., Chem. Commun. 1985, 469.
19. (b) Srikrishna, A.; Nagaraju, S.; Sharma, G. V. R. J. Chem. Soc., Chem. Commun. 1993, 285.
20. (c) Hartmann, B.; Deprés, J.-P.; Greene, A. E. Tetrahedron Lett. 1993, 34, 1487.
21. For reviews of radical cyclizations, see: (a) Giese, B. Radicals in Organic Synthesis: Formation of Carbon-Carbon Bonds; Pergamon Press: Oxford, 1986. (b) Jasperse, C. P.; Curran, D. P.; Fevig, T. L. Chem. Rev. 1991, 91, 1237. (c) Curran, D. P. Synthesis 1988, 417 and Ibid. 489. (d) Ramaiah, M. Tetrahedron 1987, 43, 3541. (e) Hart, D. J. Science 1984, 223, 883.
22. For reviews of radical cyclizations, see: (a) Giese, B. Radicals in Organic Synthesis: Formation of Carbon-Carbon Bonds; Pergamon Press: Oxford, 1986. (b) Jasperse, C. P.; Curran, D. P.; Fevig, T. L. Chem. Rev. 1991, 91, 1237. (c) Curran, D. P. Synthesis 1988, 417 and Ibid. 489. (d) Ramaiah, M. Tetrahedron 1987, 43, 3541. (e) Hart, D. J. Science 1984, 223, 883.
23. For reviews of radical cyclizations, see: (a) Giese, B. Radicals in Organic Synthesis: Formation of Carbon-Carbon Bonds; Pergamon Press: Oxford, 1986. (b) Jasperse, C. P.; Curran, D. P.; Fevig, T. L. Chem. Rev. 1991, 91, 1237. (c) Curran, D. P. Synthesis 1988, 417 and Ibid. 489. (d) Ramaiah, M. Tetrahedron 1987, 43, 3541. (e) Hart, D. J. Science 1984, 223, 883.
24. For reviews of radical cyclizations, see: (a) Giese, B. Radicals in Organic Synthesis: Formation of Carbon-Carbon Bonds; Pergamon Press: Oxford, 1986. (b) Jasperse, C. P.; Curran, D. P.; Fevig, T. L. Chem. Rev. 1991, 91, 1237. (c) Curran, D. P. Synthesis 1988, 417 and Ibid. 489. (d) Ramaiah, M. Tetrahedron 1987, 43, 3541. (e) Hart, D. J. Science 1984, 223, 883.
25. For reviews of radical cyclizations, see: (a) Giese, B. Radicals in Organic Synthesis: Formation of Carbon-Carbon Bonds; Pergamon Press: Oxford, 1986. (b) Jasperse, C. P.; Curran, D. P.; Fevig, T. L. Chem. Rev. 1991, 91, 1237. (c) Curran, D. P. Synthesis 1988, 417 and Ibid. 489. (d) Ramaiah, M. Tetrahedron 1987, 43, 3541. (e) Hart, D. J. Science 1984, 223, 883.
26. For reviews of radical cyclizations, see: (a) Giese, B. Radicals in Organic Synthesis: Formation of Carbon-Carbon Bonds; Pergamon Press: Oxford, 1986. (b) Jasperse, C. P.; Curran, D. P.; Fevig, T. L. Chem. Rev. 1991, 91, 1237. (c) Curran, D. P. Synthesis 1988, 417 and Ibid. 489. (d) Ramaiah, M. Tetrahedron 1987, 43, 3541. (e) Hart, D. J. Science 1984, 223, 883.
27. (a) Curran, D. P.; Eichenberger, E.; Collis, M.; Roepel, M. G.; Thoma, G. J. Am. Chem. Soc. 1994, 116, 4279.
28. (b) Curran, D. P.; Thoma, G. J. Am. Chem. Soc. 1992, 114, 4436.
29. (a) Byers, J. H.; Thissell, J. G.; Thomas, M. A. Tetrahedron Lett. 1995, 36, 6403.
30. (b) Byers, J. H.; Lane, G. C. J. Org. Chem. 1983, 58, 3355.
31. (c) Byers, J. H.; Harper, B. C. Tetrahedron Lett. 1992, 33, 6953.
32. (d) Byers, H. J.; Gleason, T. G.; Knight, K. S. J. Chem. Soc., Chem. Commun. 1991, 354.
33. (e) Byers, J. H.; Lane, G. C. Tetrahedron Lett. 1990, 31, 5697.
34. Preliminary communication: Back, T. G.; Gladstone, P. L. Synlett 1993, 699.
35. The term radical spirocyclization has recently been employed to describe the formation of other spiro structures by radical reactions: (a) Clive, D. L. J.; Tao, Y.; Khodabocus, A.; Wu, Y.-J.; Angoh, A. G.; Bennett, S. M.; Boddy, C. N.; Bordeleau, L.; Kellner, D.; Kleiner, G.; Middleton, D. S.; Nichols, C. J.; Richardson, S. R.; Vernon, P. G. J. Am. Chem. Soc. 1994, 116, 11275. (b) Clive, D. L. J.; Angoh, A. G.; Bennett, S. M. J. Org. Chem. 1987, 52, 1339.
36. The term radical spirocyclization has recently been employed to describe the formation of other spiro structures by radical reactions: (a) Clive, D. L. J.; Tao, Y.; Khodabocus, A.; Wu, Y.-J.; Angoh, A. G.; Bennett, S. M.; Boddy, C. N.; Bordeleau, L.; Kellner, D.; Kleiner, G.; Middleton, D. S.; Nichols, C. J.; Richardson, S. R.; Vernon, P. G. J. Am. Chem. Soc. 1994, 116, 11275. (b) Clive, D. L. J.; Angoh, A. G.; Bennett, S. M. J. Org. Chem. 1987, 52, 1339.
37. (a) Reich, H .J.; Renga, J. M.; Reich, I. L. J. Org. Chem. 1974, 39, 2133.
38. (b) Reich, H. J.; Renga, J. M.; Reich, I. L. J. Am. Chem. Soc. 1975, 97, 5434.
39. For reviews of cyclizations mediated by electrophilic selenium compounds, see: (a) Nicolaou, K. C.; Petasis, N. A.; Claremon, D. A. In Organoselenium Chemistry; Liotta, D., Ed.; Wiley: New York, 1987; Chapter 2. (b) Paulmier, C. In Selenium Reagents and Intermediates in Organic Synthesis; Pergamon Press: Oxford, 1986; Chapter 8. (c) Back, T. G. In The Chemistry of Organic Selenium and Tellurium Compounds; Patai, S., Ed.; Wiley: Chichester, 1987; Volume 2, Chapter 3.
40. For reviews of cyclizations mediated by electrophilic selenium compounds, see: (a) Nicolaou, K. C.; Petasis, N. A.; Claremon, D. A. In Organoselenium Chemistry; Liotta, D., Ed.; Wiley: New York, 1987; Chapter 2. (b) Paulmier, C. In Selenium Reagents and Intermediates in Organic Synthesis; Pergamon Press: Oxford, 1986; Chapter 8. (c) Back, T. G. In The Chemistry of Organic Selenium and Tellurium Compounds; Patai, S., Ed.; Wiley: Chichester, 1987; Volume 2, Chapter 3.
41. For reviews of cyclizations mediated by electrophilic selenium compounds, see: (a) Nicolaou, K. C.; Petasis, N. A.; Claremon, D. A. In Organoselenium Chemistry; Liotta, D., Ed.; Wiley: New York, 1987; Chapter 2. (b) Paulmier, C. In Selenium Reagents and Intermediates in Organic Synthesis; Pergamon Press: Oxford, 1986; Chapter 8. (c) Back, T. G. In The Chemistry of Organic Selenium and Tellurium Compounds; Patai, S., Ed.; Wiley: Chichester, 1987; Volume 2, Chapter 3.
42. For examples of cyclizations of unsaturated β-dicarbonyl compounds with selenium electrophiles, see (a) Ley, S. V.; Murray, P. J.; Palmer, B. D. Tetrahedron 1985, 41, 4765. (b) Ley, S. V.; Lygo, B.; Molines, H. J. Chem. Soc., Perkin Trans. 1 1984, 2403. (c) Ley, S. V.; Murray, P. J. J. Chem. Soc., Chem. Commun. 1982, 1252. (d) Ley, S. V.; Lygo, B.; Molines, H.; Morton, J. A. J. Chem. Soc., Chem. Commun. 1982, 1251. (e) Jackson, W. P.; Ley, S. V.; Morton, J. A. J. Chem. Soc., Chem. Commun. 1980, 1028. (f) Jackson, W. P.; Ley, S. V.; Whittle, A. J. J. Chem. Soc., Chem. Commun. 1980, 1173. (g) Alderdice, M.; Weiler, L. Can. J. Chem. 1981, 59, 2239.
43. For examples of cyclizations of unsaturated β-dicarbonyl compounds with selenium electrophiles, see (a) Ley, S. V.; Murray, P. J.; Palmer, B. D. Tetrahedron 1985, 41, 4765. (b) Ley, S. V.; Lygo, B.; Molines, H. J. Chem. Soc., Perkin Trans. 1 1984, 2403. (c) Ley, S. V.; Murray, P. J. J. Chem. Soc., Chem. Commun. 1982, 1252. (d) Ley, S. V.; Lygo, B.; Molines, H.; Morton, J. A. J. Chem. Soc., Chem. Commun. 1982, 1251. (e) Jackson, W. P.; Ley, S. V.; Morton, J. A. J. Chem. Soc., Chem. Commun. 1980, 1028. (f) Jackson, W. P.; Ley, S. V.; Whittle, A. J. J. Chem. Soc., Chem. Commun. 1980, 1173. (g) Alderdice, M.; Weiler, L. Can. J. Chem. 1981, 59, 2239.
44. For examples of cyclizations of unsaturated β-dicarbonyl compounds with selenium electrophiles, see (a) Ley, S. V.; Murray, P. J.; Palmer, B. D. Tetrahedron 1985, 41, 4765. (b) Ley, S. V.; Lygo, B.; Molines, H. J. Chem. Soc., Perkin Trans. 1 1984, 2403. (c) Ley, S. V.; Murray, P. J. J. Chem. Soc., Chem. Commun. 1982, 1252. (d) Ley, S. V.; Lygo, B.; Molines, H.; Morton, J. A. J. Chem. Soc., Chem. Commun. 1982, 1251. (e) Jackson, W. P.; Ley, S. V.; Morton, J. A. J. Chem. Soc., Chem. Commun. 1980, 1028. (f) Jackson, W. P.; Ley, S. V.; Whittle, A. J. J. Chem. Soc., Chem. Commun. 1980, 1173. (g) Alderdice, M.; Weiler, L. Can. J. Chem. 1981, 59, 2239.
45. For examples of cyclizations of unsaturated β-dicarbonyl compounds with selenium electrophiles, see (a) Ley, S. V.; Murray, P. J.; Palmer, B. D. Tetrahedron 1985, 41, 4765. (b) Ley, S. V.; Lygo, B.; Molines, H. J. Chem. Soc., Perkin Trans. 1 1984, 2403. (c) Ley, S. V.; Murray, P. J. J. Chem. Soc., Chem. Commun. 1982, 1252. (d) Ley, S. V.; Lygo, B.; Molines, H.; Morton, J. A. J. Chem. Soc., Chem. Commun. 1982, 1251. (e) Jackson, W. P.; Ley, S. V.; Morton, J. A. J. Chem. Soc., Chem. Commun. 1980, 1028. (f) Jackson, W. P.; Ley, S. V.; Whittle, A. J. J. Chem. Soc., Chem. Commun. 1980, 1173. (g) Alderdice, M.; Weiler, L. Can. J. Chem. 1981, 59, 2239.
46. For examples of cyclizations of unsaturated β-dicarbonyl compounds with selenium electrophiles, see (a) Ley, S. V.; Murray, P. J.; Palmer, B. D. Tetrahedron 1985, 41, 4765. (b) Ley, S. V.; Lygo, B.; Molines, H. J. Chem. Soc., Perkin Trans. 1 1984, 2403. (c) Ley, S. V.; Murray, P. J. J. Chem. Soc., Chem. Commun. 1982, 1252. (d) Ley, S. V.; Lygo, B.; Molines, H.; Morton, J. A. J. Chem. Soc., Chem. Commun. 1982, 1251. (e) Jackson, W. P.; Ley, S. V.; Morton, J. A. J. Chem. Soc., Chem. Commun. 1980, 1028. (f) Jackson, W. P.; Ley, S. V.; Whittle, A. J. J. Chem. Soc., Chem. Commun. 1980, 1173. (g) Alderdice, M.; Weiler, L. Can. J. Chem. 1981, 59, 2239.
47. For examples of cyclizations of unsaturated β-dicarbonyl compounds with selenium electrophiles, see (a) Ley, S. V.; Murray, P. J.; Palmer, B. D. Tetrahedron 1985, 41, 4765. (b) Ley, S. V.; Lygo, B.; Molines, H. J. Chem. Soc., Perkin Trans. 1 1984, 2403. (c) Ley, S. V.; Murray, P. J. J. Chem. Soc., Chem. Commun. 1982, 1252. (d) Ley, S. V.; Lygo, B.; Molines, H.; Morton, J. A. J. Chem. Soc., Chem. Commun. 1982, 1251. (e) Jackson, W. P.; Ley, S. V.; Morton, J. A. J. Chem. Soc., Chem. Commun. 1980, 1028. (f) Jackson, W. P.; Ley, S. V.; Whittle, A. J. J. Chem. Soc., Chem. Commun. 1980, 1173. (g) Alderdice, M.; Weiler, L. Can. J. Chem. 1981, 59, 2239.
48. For examples of cyclizations of unsaturated β-dicarbonyl compounds with selenium electrophiles, see (a) Ley, S. V.; Murray, P. J.; Palmer, B. D. Tetrahedron 1985, 41, 4765. (b) Ley, S. V.; Lygo, B.; Molines, H. J. Chem. Soc., Perkin Trans. 1 1984, 2403. (c) Ley, S. V.; Murray, P. J. J. Chem. Soc., Chem. Commun. 1982, 1252. (d) Ley, S. V.; Lygo, B.; Molines, H.; Morton, J. A. J. Chem. Soc., Chem. Commun. 1982, 1251. (e) Jackson, W. P.; Ley, S. V.; Morton, J. A. J. Chem. Soc., Chem. Commun. 1980, 1028. (f) Jackson, W. P.; Ley, S. V.; Whittle, A. J. J. Chem. Soc., Chem. Commun. 1980, 1173. (g) Alderdice, M.; Weiler, L. Can. J. Chem. 1981, 59, 2239.
49. Jackson, W. P.; Ley, S. V.; Morton, J. A. Tetrahedron Lett. 1981, 22, 1981.
50. For general reviews, see: (a) Carruthers, W. Cycloaddition Reactions in Organic Synthesis; Pergamon Press: Oxford, 1990. (b) Oppolzer, W. In Comprehensive Organic Synthesis, Trost, B. M., Ed.; Pergamon Press: Oxford, 1991; Volume 5, Chapter 4.1.
51. For general reviews, see: (a) Carruthers, W. Cycloaddition Reactions in Organic Synthesis; Pergamon Press: Oxford, 1990. (b) Oppolzer, W. In Comprehensive Organic Synthesis, Trost, B. M., Ed.; Pergamon Press: Oxford, 1991; Volume 5, Chapter 4.1.
52. Fleming, I. Frontier Orbitals and Organic Chemical Reactions; Wiley: Chichester, 1976; Chapter 4.
53. For example, 2-methylcyclopent-2-enone reacts with piperylene to afford the vicinal dimethyl regioisomer with high selectivity: Fringuelli, F.; Pizzo, F.; Taticchi, A.; Halls, T. D. J.; Wenkert, E. J. Org. Chem. 1982, 47, 5056.
54. For a review of the facial selectivity of Diels-Alder reactions, see: Fallis, A. G.; Lu, Y.-F. Adv. Cycloaddit. 1993, 3, 1.
55. For a review of the enhancement of Diels-Alder reactions with Lewis acids and by other methods, see: Pindur, U.; Lutz, G.; Otto, C. Chem. Rev. 1993, 93, 741.
56. Breslow, R. Acc. Chem. Res. 1991, 24, 159.
57. Grieco, P. A.; Nunes, J. J.; Gaul, M. D. J. Am. Chem. Soc. 1990, 112, 4595.
58. For reviews of high pressure Diels-Alder reactions, see: (a) Ibata, T. In Organic Synthesis at High Pressures, Matsumoto, K.; Acheson, R. M., Eds.; Wiley: New York, 1991; Chapter 9. (b) Jenner, G. In Organic High Pressure Chemistry; Le Noble, W. J., Ed.; Elsevier: Amsterdam, 1988; Chapter 6. (c) Jurczak, J. Ibid., Chapter 11. (d) Van Eldik, R.; Asano, T.; Le Noble, W. J. Chem. Rev. 1989, 89, 549. (e) Matsumoto, K.; Sera, A. Synthesis 1985, 999.
59. For reviews of high pressure Diels-Alder reactions, see: (a) Ibata, T. In Organic Synthesis at High Pressures, Matsumoto, K.; Acheson, R. M., Eds.; Wiley: New York, 1991; Chapter 9. (b) Jenner, G. In Organic High Pressure Chemistry; Le Noble, W. J., Ed.; Elsevier: Amsterdam, 1988; Chapter 6. (c) Jurczak, J. Ibid., Chapter 11. (d) Van Eldik, R.; Asano, T.; Le Noble, W. J. Chem. Rev. 1989, 89, 549. (e) Matsumoto, K.; Sera, A. Synthesis 1985, 999.
60. For reviews of high pressure Diels-Alder reactions, see: (a) Ibata, T. In Organic Synthesis at High Pressures, Matsumoto, K.; Acheson, R. M., Eds.; Wiley: New York, 1991; Chapter 9. (b) Jenner, G. In Organic High Pressure Chemistry; Le Noble, W. J., Ed.; Elsevier: Amsterdam, 1988; Chapter 6. (c) Jurczak, J. Ibid., Chapter 11. (d) Van Eldik, R.; Asano, T.; Le Noble, W. J. Chem. Rev. 1989, 89, 549. (e) Matsumoto, K.; Sera, A. Synthesis 1985, 999.
61. For reviews of high pressure Diels-Alder reactions, see: (a) Ibata, T. In Organic Synthesis at High Pressures, Matsumoto, K.; Acheson, R. M., Eds.; Wiley: New York, 1991; Chapter 9. (b) Jenner, G. In Organic High Pressure Chemistry; Le Noble, W. J., Ed.; Elsevier: Amsterdam, 1988; Chapter 6. (c) Jurczak, J. Ibid., Chapter 11. (d) Van Eldik, R.; Asano, T.; Le Noble, W. J. Chem. Rev. 1989, 89, 549. (e) Matsumoto, K.; Sera, A. Synthesis 1985, 999.
62. For reviews of high pressure Diels-Alder reactions, see: (a) Ibata, T. In Organic Synthesis at High Pressures, Matsumoto, K.; Acheson, R. M., Eds.; Wiley: New York, 1991; Chapter 9. (b) Jenner, G. In Organic High Pressure Chemistry; Le Noble, W. J., Ed.; Elsevier: Amsterdam, 1988; Chapter 6. (c) Jurczak, J. Ibid., Chapter 11. (d) Van Eldik, R.; Asano, T.; Le Noble, W. J. Chem. Rev. 1989, 89, 549. (e) Matsumoto, K.; Sera, A. Synthesis 1985, 999.
63. Since the catalyst itself is homochiral in this example, it raises the possibility of enantioselective cycloaddition by kinetic resolution of the racemic dienophile. This is not the focus of the present work, however, and this aspect was not investigated further. For a review of Ti-TADDOL complexes and related compounds, see: Duthaler, R. O.; Hafner, A. Chem. Rev. 1992, 92, 807.
64. In several other examples studied, increased pressure also enhanced the amount of endo vs exo addition, although to a relatively small degree. Seguchi, K.; Sera, A.; Maruyama, K. Tetrahedron Lett. 1973, 1585.
65. (a) The opening of cyclohexene epoxides is subject to the Fürst-Plattner rule: Fürst, A.; Plattner, P. A. Abstracts of Papers of the 12th International Congress of Pure and Applied Chemistry 1951, IUPAC: New York, p 409; via Eliel, E. L.; Wilen, S. H.; Mander, L. N. Stereochemistry of Organic Compounds; Wiley: New York, 1994; p 730. (b) For a discussion of the stereoelectronic effects underlying the Fürst-Plattner rule, see Deslongchamps, P. In Stereoelectronic Effects in Organic Chemistry; Pergamon Press: Oxford, 1983; Chapter 5.
66. (a) The opening of cyclohexene epoxides is subject to the Fürst-Plattner rule: Fürst, A.; Plattner, P. A. Abstracts of Papers of the 12th International Congress of Pure and Applied Chemistry 1951, IUPAC: New York, p 409; via Eliel, E. L.; Wilen, S. H.; Mander, L. N. Stereochemistry of Organic Compounds; Wiley: New York, 1994; p 730. (b) For a discussion of the stereoelectronic effects underlying the Fürst-Plattner rule, see Deslongchamps, P. In Stereoelectronic Effects in Organic Chemistry; Pergamon Press: Oxford, 1983; Chapter 5.
67. (a) The opening of cyclohexene epoxides is subject to the Fürst-Plattner rule: Fürst, A.; Plattner, P. A. Abstracts of Papers of the 12th International Congress of Pure and Applied Chemistry 1951, IUPAC: New York, p 409; via Eliel, E. L.; Wilen, S. H.; Mander, L. N. Stereochemistry of Organic Compounds; Wiley: New York, 1994; p 730. (b) For a discussion of the stereoelectronic effects underlying the Fürst-Plattner rule, see Deslongchamps, P. In Stereoelectronic Effects in Organic Chemistry; Pergamon Press: Oxford, 1983; Chapter 5.
68. Palumbo, G.; Ferreri, C.; Caputo, R. Tetrahedron Lett. 1983, 24, 1307.
69. Other attempts to reduce the epoxide with hydride reducing agents, or with Se or Te nucleophiles, followed by reductive deselenization/detellurization, proved less effective.
70. The authors have deposited atomic coordinates for structures 28 and 39 with the Cambridge Crystallographic Data Centre. The coordinates can be obtained, on request, from the Director, Cambridge Crystallographic Data Centre, 12 Union Road, Cambridge, CB2 1EZ, U.K.
71. Molecular modeling was carried out with MacroModel version 3.5a, Columbia University, 1992. Local energy minima were calculated with the MM2 force field, and the global minimum energy conformations were determined by Monte Carlo searches using 1000 structures within 50 kJ/mol of the global minimum.
72. (a) Allyl cyanoformate proved a superior reagent to allyl carbonate or allyl chloroformate in this case, but was inferior to allyl chloroformate for the acylations shown in Scheme 2. (b) The use of methyl cyanoformate for the acylation of ketone enolates has been previously reported: Mander, L. N.; Sethi, S. P. Tetrahedron Lett. 1983, 24, 5425. (c) Allyl cyanoformate was prepared by the method of: Donnelly, D. M. X.; Finet, J.-P.; Rattigan, B. A. J. Chem. Soc., Perkin Trans. 1 1993, 1729.
73. (a) Allyl cyanoformate proved a superior reagent to allyl carbonate or allyl chloroformate in this case, but was inferior to allyl chloroformate for the acylations shown in Scheme 2. (b) The use of methyl cyanoformate for the acylation of ketone enolates has been previously reported: Mander, L. N.; Sethi, S. P. Tetrahedron Lett. 1983, 24, 5425. (c) Allyl cyanoformate was prepared by the method of: Donnelly, D. M. X.; Finet, J.-P.; Rattigan, B. A. J. Chem. Soc., Perkin Trans. 1 1993, 1729.
74. (a) Allyl cyanoformate proved a superior reagent to allyl carbonate or allyl chloroformate in this case, but was inferior to allyl chloroformate for the acylations shown in Scheme 2. (b) The use of methyl cyanoformate for the acylation of ketone enolates has been previously reported: Mander, L. N.; Sethi, S. P. Tetrahedron Lett. 1983, 24, 5425. (c) Allyl cyanoformate was prepared by the method of: Donnelly, D. M. X.; Finet, J.-P.; Rattigan, B. A. J. Chem. Soc., Perkin Trans. 1 1993, 1729.
75. Dijkgraaf, C.; Rousseau, J. P. G. Spectrochim. Acta 1968, 24A, 1213.
76. Narasaka, K.; Iwasawa, N.; Inoue, M.; Yamada, T.; Nakashima, M.; Sugimori, J. J. Am. Chem. Soc. 1989, 111, 5340.
77. Schwartz, N. N.; Blumbergs, J. H. J. Org. Chem. 1964, 29, 1976.
78. Typically, the more reactive trans isomer of piperylene reacts selectively when a cis,trans mixture is employed in normal Diels-Alder reactions. The use of pure trans-piperylene in several experiments at high pressure conferred no advantage over the mixture.
79. Stork, G.; Brizzolara, A.; Landesman, H.; Szmuszkovicz, J.; Terrell, R. J. Am. Chem. Soc. 1963, 85, 207.
80. Corey, E. J.; Schmidt, G. Tetrahedron Lett. 1979, 399.
81. Corey, E. J.; Venkateswarlu, A. J. Am. Chem. Soc. 1972, 94, 6190.