Enantioselective double Michael addition/cyclization with an oxygen- centered nucleophile as the first step in a concise synthesis of natural (+)- asteriscanolide

Journal of the American Chemical Society

Volumn 122, Issue 12, 2000, Pages 2742-2748

  Paquette, Leo A ^a   Tae, Jinsung ^a   Arrington, Mark P ^a   Sadoun, Aladin H ^a  

^a OHIO STATE UNIVERSITY   (United States)

Author keywords

[No Author keywords available]

Indexed keywords

CYCLOPENTENONE DERIVATIVE; OXIDE; OXYGEN; RUTHENIUM DERIVATIVE; SESQUITERPENE DERIVATIVE;

ARTICLE; CHEMICAL REACTION; CYCLIZATION; OXIDATION; REACTION ANALYSIS; STEREOCHEMISTRY; SYNTHESIS;

EID: 0034728569     PISSN: 00027863     EISSN: None     Source Type: Journal    
DOI: 10.1021/ja994053w     Document Type: Article

References (96)

1. San Feliciano, A.; Barrero, A. F.; Medarde, M.; Miguel del Corral, J. M.; Aramburu, A.; Perales, A.; Fayos, J. Tetrahedron Lett. 1985, 26, 2369.
2. (a) Petasis, N. A.; Patane, M. A. Tetrahedron 1992, 48, 5757.
3. (b) Rousseau, G. Tetrahedron 1995, 51, 2777.
4. (c) Mehta, G.; Singh, V. Chem. Rev. 1999, 99, 81.
5. Wender, P. A.; Ihle, N. C.; Correia, C. R. D. J. Am. Chem. Soc. 1988, 110, 5904.
6. Booker-Milburn, K. I.; Cowell, J. K.; Harris, L. J. Tetrahedron 1997, 53, 12319.
7. Mehta, G.; Murty, A. N. J. Org. Chem. 1990, 55, 3568.
8. (a) Booker-Milburn, K. I.; Cowell, J. K.; Harris, L. J. Tetrahedron Lett. 1994, 35, 3883.
9. (b) Booker-Milburn, K. I.; Cowell, J. K. Tetrahedron Lett. 1996, 37, 2177.
10. Lange, G. L.; Organ, M. G. J. Org. Chem. 1996, 61, 5358.
11. Sarkar, T. K.; Gangopadhyay, P.; Ghorai, B. K.; Nandy, S. K.; Fang, J.-M. Tetrahedron Lett. 1998, 39, 8365.
12. Cheung, Y. Y.; Krafft, M. E.; Juliano-Capucao, C. A. Book of Abstracts, 216th ACS National Meeting, Boston, August 23-27, 1998: American Chemical Soceity: Washington, DC, 1998; ORGN-238.
13. Liu, S.; Crowe, W. E. Book of Abstracts, 216th ACS National Meeting, Boston, August 23-27, 1998; American Chemical Soceity: Washington, DC, ORGN-235.
14. Table 2 in the 1998 review by S. K. Armstrong [J. Chem. Soc., Perkin Trans. 1 1998, 371] dramatically points to the dearth of eight-membered ring examples as of that date.
15. For recent reviews, consult: (a) Grubbs, R. H.; Miller, S. J.; Fu, G. C. Acc. Chem. Res. 1995, 28, 446. (b) Schmalz, H.-G. Angew. Chem., Int. Ed. Engl. 1995, 34, 1833. (c) Fürstner, A. Topics Catal. 1997, 4, 285. (d) Schuster, M.; Blechert, S. Angew. Chem., Int. Ed. Engl. 1997, 36, 2037. (e) Fürstner, A.; Langemann, K. Synthesis 1997, 792. (f) Philips, A. J.; Abell, A. D. Aldrichim. Acta 1999, 32, 75. (g) Pariya, C.; Jayaprakash, K. N.; Sarkar, A. Coord. Chem. Rev. 1998, 168, 1. (h) Randall, M. L.; Snapper, M. L. J. Mol. Catal. A: Chem. 1998, 133, 29. (i) Grubbs, R. H.; Chang, S. Tetrahedron 1998, 54, 4413. (j) Ivin, K. J. J. Mol. Catal. A: Chem. 1998, 133, 1. (k) Wright, D. L. Curr. Org. Chem. 1999, 3, 211.
16. For recent reviews, consult: (a) Grubbs, R. H.; Miller, S. J.; Fu, G. C. Acc. Chem. Res. 1995, 28, 446. (b) Schmalz, H.-G. Angew. Chem., Int. Ed. Engl. 1995, 34, 1833. (c) Fürstner, A. Topics Catal. 1997, 4, 285. (d) Schuster, M.; Blechert, S. Angew. Chem., Int. Ed. Engl. 1997, 36, 2037. (e) Fürstner, A.; Langemann, K. Synthesis 1997, 792. (f) Philips, A. J.; Abell, A. D. Aldrichim. Acta 1999, 32, 75. (g) Pariya, C.; Jayaprakash, K. N.; Sarkar, A. Coord. Chem. Rev. 1998, 168, 1. (h) Randall, M. L.; Snapper, M. L. J. Mol. Catal. A: Chem. 1998, 133, 29. (i) Grubbs, R. H.; Chang, S. Tetrahedron 1998, 54, 4413. (j) Ivin, K. J. J. Mol. Catal. A: Chem. 1998, 133, 1. (k) Wright, D. L. Curr. Org. Chem. 1999, 3, 211.
17. For recent reviews, consult: (a) Grubbs, R. H.; Miller, S. J.; Fu, G. C. Acc. Chem. Res. 1995, 28, 446. (b) Schmalz, H.-G. Angew. Chem., Int. Ed. Engl. 1995, 34, 1833. (c) Fürstner, A. Topics Catal. 1997, 4, 285. (d) Schuster, M.; Blechert, S. Angew. Chem., Int. Ed. Engl. 1997, 36, 2037. (e) Fürstner, A.; Langemann, K. Synthesis 1997, 792. (f) Philips, A. J.; Abell, A. D. Aldrichim. Acta 1999, 32, 75. (g) Pariya, C.; Jayaprakash, K. N.; Sarkar, A. Coord. Chem. Rev. 1998, 168, 1. (h) Randall, M. L.; Snapper, M. L. J. Mol. Catal. A: Chem. 1998, 133, 29. (i) Grubbs, R. H.; Chang, S. Tetrahedron 1998, 54, 4413. (j) Ivin, K. J. J. Mol. Catal. A: Chem. 1998, 133, 1. (k) Wright, D. L. Curr. Org. Chem. 1999, 3, 211.
18. For recent reviews, consult: (a) Grubbs, R. H.; Miller, S. J.; Fu, G. C. Acc. Chem. Res. 1995, 28, 446. (b) Schmalz, H.-G. Angew. Chem., Int. Ed. Engl. 1995, 34, 1833. (c) Fürstner, A. Topics Catal. 1997, 4, 285. (d) Schuster, M.; Blechert, S. Angew. Chem., Int. Ed. Engl. 1997, 36, 2037. (e) Fürstner, A.; Langemann, K. Synthesis 1997, 792. (f) Philips, A. J.; Abell, A. D. Aldrichim. Acta 1999, 32, 75. (g) Pariya, C.; Jayaprakash, K. N.; Sarkar, A. Coord. Chem. Rev. 1998, 168, 1. (h) Randall, M. L.; Snapper, M. L. J. Mol. Catal. A: Chem. 1998, 133, 29. (i) Grubbs, R. H.; Chang, S. Tetrahedron 1998, 54, 4413. (j) Ivin, K. J. J. Mol. Catal. A: Chem. 1998, 133, 1. (k) Wright, D. L. Curr. Org. Chem. 1999, 3, 211.
19. For recent reviews, consult: (a) Grubbs, R. H.; Miller, S. J.; Fu, G. C. Acc. Chem. Res. 1995, 28, 446. (b) Schmalz, H.-G. Angew. Chem., Int. Ed. Engl. 1995, 34, 1833. (c) Fürstner, A. Topics Catal. 1997, 4, 285. (d) Schuster, M.; Blechert, S. Angew. Chem., Int. Ed. Engl. 1997, 36, 2037. (e) Fürstner, A.; Langemann, K. Synthesis 1997, 792. (f) Philips, A. J.; Abell, A. D. Aldrichim. Acta 1999, 32, 75. (g) Pariya, C.; Jayaprakash, K. N.; Sarkar, A. Coord. Chem. Rev. 1998, 168, 1. (h) Randall, M. L.; Snapper, M. L. J. Mol. Catal. A: Chem. 1998, 133, 29. (i) Grubbs, R. H.; Chang, S. Tetrahedron 1998, 54, 4413. (j) Ivin, K. J. J. Mol. Catal. A: Chem. 1998, 133, 1. (k) Wright, D. L. Curr. Org. Chem. 1999, 3, 211.
20. For recent reviews, consult: (a) Grubbs, R. H.; Miller, S. J.; Fu, G. C. Acc. Chem. Res. 1995, 28, 446. (b) Schmalz, H.-G. Angew. Chem., Int. Ed. Engl. 1995, 34, 1833. (c) Fürstner, A. Topics Catal. 1997, 4, 285. (d) Schuster, M.; Blechert, S. Angew. Chem., Int. Ed. Engl. 1997, 36, 2037. (e) Fürstner, A.; Langemann, K. Synthesis 1997, 792. (f) Philips, A. J.; Abell, A. D. Aldrichim. Acta 1999, 32, 75. (g) Pariya, C.; Jayaprakash, K. N.; Sarkar, A. Coord. Chem. Rev. 1998, 168, 1. (h) Randall, M. L.; Snapper, M. L. J. Mol. Catal. A: Chem. 1998, 133, 29. (i) Grubbs, R. H.; Chang, S. Tetrahedron 1998, 54, 4413. (j) Ivin, K. J. J. Mol. Catal. A: Chem. 1998, 133, 1. (k) Wright, D. L. Curr. Org. Chem. 1999, 3, 211.
21. For recent reviews, consult: (a) Grubbs, R. H.; Miller, S. J.; Fu, G. C. Acc. Chem. Res. 1995, 28, 446. (b) Schmalz, H.-G. Angew. Chem., Int. Ed. Engl. 1995, 34, 1833. (c) Fürstner, A. Topics Catal. 1997, 4, 285. (d) Schuster, M.; Blechert, S. Angew. Chem., Int. Ed. Engl. 1997, 36, 2037. (e) Fürstner, A.; Langemann, K. Synthesis 1997, 792. (f) Philips, A. J.; Abell, A. D. Aldrichim. Acta 1999, 32, 75. (g) Pariya, C.; Jayaprakash, K. N.; Sarkar, A. Coord. Chem. Rev. 1998, 168, 1. (h) Randall, M. L.; Snapper, M. L. J. Mol. Catal. A: Chem. 1998, 133, 29. (i) Grubbs, R. H.; Chang, S. Tetrahedron 1998, 54, 4413. (j) Ivin, K. J. J. Mol. Catal. A: Chem. 1998, 133, 1. (k) Wright, D. L. Curr. Org. Chem. 1999, 3, 211.
22. For recent reviews, consult: (a) Grubbs, R. H.; Miller, S. J.; Fu, G. C. Acc. Chem. Res. 1995, 28, 446. (b) Schmalz, H.-G. Angew. Chem., Int. Ed. Engl. 1995, 34, 1833. (c) Fürstner, A. Topics Catal. 1997, 4, 285. (d) Schuster, M.; Blechert, S. Angew. Chem., Int. Ed. Engl. 1997, 36, 2037. (e) Fürstner, A.; Langemann, K. Synthesis 1997, 792. (f) Philips, A. J.; Abell, A. D. Aldrichim. Acta 1999, 32, 75. (g) Pariya, C.; Jayaprakash, K. N.; Sarkar, A. Coord. Chem. Rev. 1998, 168, 1. (h) Randall, M. L.; Snapper, M. L. J. Mol. Catal. A: Chem. 1998, 133, 29. (i) Grubbs, R. H.; Chang, S. Tetrahedron 1998, 54, 4413. (j) Ivin, K. J. J. Mol. Catal. A: Chem. 1998, 133, 1. (k) Wright, D. L. Curr. Org. Chem. 1999, 3, 211.
23. For recent reviews, consult: (a) Grubbs, R. H.; Miller, S. J.; Fu, G. C. Acc. Chem. Res. 1995, 28, 446. (b) Schmalz, H.-G. Angew. Chem., Int. Ed. Engl. 1995, 34, 1833. (c) Fürstner, A. Topics Catal. 1997, 4, 285. (d) Schuster, M.; Blechert, S. Angew. Chem., Int. Ed. Engl. 1997, 36, 2037. (e) Fürstner, A.; Langemann, K. Synthesis 1997, 792. (f) Philips, A. J.; Abell, A. D. Aldrichim. Acta 1999, 32, 75. (g) Pariya, C.; Jayaprakash, K. N.; Sarkar, A. Coord. Chem. Rev. 1998, 168, 1. (h) Randall, M. L.; Snapper, M. L. J. Mol. Catal. A: Chem. 1998, 133, 29. (i) Grubbs, R. H.; Chang, S. Tetrahedron 1998, 54, 4413. (j) Ivin, K. J. J. Mol. Catal. A: Chem. 1998, 133, 1. (k) Wright, D. L. Curr. Org. Chem. 1999, 3, 211.
24. For recent reviews, consult: (a) Grubbs, R. H.; Miller, S. J.; Fu, G. C. Acc. Chem. Res. 1995, 28, 446. (b) Schmalz, H.-G. Angew. Chem., Int. Ed. Engl. 1995, 34, 1833. (c) Fürstner, A. Topics Catal. 1997, 4, 285. (d) Schuster, M.; Blechert, S. Angew. Chem., Int. Ed. Engl. 1997, 36, 2037. (e) Fürstner, A.; Langemann, K. Synthesis 1997, 792. (f) Philips, A. J.; Abell, A. D. Aldrichim. Acta 1999, 32, 75. (g) Pariya, C.; Jayaprakash, K. N.; Sarkar, A. Coord. Chem. Rev. 1998, 168, 1. (h) Randall, M. L.; Snapper, M. L. J. Mol. Catal. A: Chem. 1998, 133, 29. (i) Grubbs, R. H.; Chang, S. Tetrahedron 1998, 54, 4413. (j) Ivin, K. J. J. Mol. Catal. A: Chem. 1998, 133, 1. (k) Wright, D. L. Curr. Org. Chem. 1999, 3, 211.
25. For recent reviews, consult: (a) Grubbs, R. H.; Miller, S. J.; Fu, G. C. Acc. Chem. Res. 1995, 28, 446. (b) Schmalz, H.-G. Angew. Chem., Int. Ed. Engl. 1995, 34, 1833. (c) Fürstner, A. Topics Catal. 1997, 4, 285. (d) Schuster, M.; Blechert, S. Angew. Chem., Int. Ed. Engl. 1997, 36, 2037. (e) Fürstner, A.; Langemann, K. Synthesis 1997, 792. (f) Philips, A. J.; Abell, A. D. Aldrichim. Acta 1999, 32, 75. (g) Pariya, C.; Jayaprakash, K. N.; Sarkar, A. Coord. Chem. Rev. 1998, 168, 1. (h) Randall, M. L.; Snapper, M. L. J. Mol. Catal. A: Chem. 1998, 133, 29. (i) Grubbs, R. H.; Chang, S. Tetrahedron 1998, 54, 4413. (j) Ivin, K. J. J. Mol. Catal. A: Chem. 1998, 133, 1. (k) Wright, D. L. Curr. Org. Chem. 1999, 3, 211.
26. (a) König, B.; Horn, C. Synlett 1996, 1013.
27. (b) Clark, J. S.; Kettle, J. G. Tetrahedron Lett. 1997, 38, 127.
28. (c) Chang, S.; Grubbs, R. H. Tetrahedron Lett. 1997, 38, 4757.
29. (d) Delgado, M.; Martin, J. D. Tetrahedron Lett. 1997, 38, 6299.
30. (e) Linderman, R. J.; Siedliecki, J.; O'Neill, S. A.; Sun, H. J. Am. Chem. Soc. 1997, 119, 6919.
31. (f) Crimmins, M. T.; Choy, A. L. J. Org. Chem. 1997, 62, 7548.
32. (g) Joe, D.; Overman, L. E. Tetrahedron Lett. 1997, 38, 8635.
33. (h) Rutjes, F. P. J. T.; Kooistra, T. M.; Hiemstra, H.; Schoemaker, H. E. Synlett 1998, 192.
34. (i) Stefinovic, M.; Snieckus, V. J. Org. Chem. 1998, 63, 2808.
35. (j) Oishi, T.; Nagumo, Y.; Hirama, M. Chem. Commun. 1998, 1041.
36. (k) Clark, J. S.; Hamelin, O.; Hufton, R. Tetrahedron Lett. 1998, 39, 8321.
37. (l) Edwards, S. D.; Lewis, T.; Taylor, R. J. K. Tetrahedron Lett. 1999, 40, 4267.
38. (m) Delgado, M.; Martin, J. D. J. Org. Chem. 1999, 64, 4798.
39. (n) Crimmins, M. T.; Choy, A. L. J. Am. Chem. Soc. 1999, 121, 5653.
40. (o) Clark, J. S.; Kettle, J. G. Tetrahedron 1999, 55, 8248.
41. (p) Crimmins, M. T.; Emmitte, K. A. Org. Lett. 1999, 1, 2029.
42. (a) Pandit, U. K.; Borer, B. C.; Bieräugel, H. Pure Appl. Chem. 1996, 68, 659.
43. (b) Barrett, A. G. M.; Baugh, S. P. D.; Gibson, V. C.; Giles, M. R.; Marshall, E. L.; Procopiou, P. A. Chem. Commun. 1996, 2231.
44. (c) Winkler, J. D.; Stelmach, J. E.; Axten, J. Tetrahedron Lett. 1996, 37, 4317.
45. (d) Miller, S. J.; Blackwell, H. E.; Grubbs, R. H. J. Am. Chem. Soc. 1996, 118, 9606.
46. (e) Barrett, A. G. M.; Baugh, S. P. D.; Gibson, V. C.; Giles, M. R.; Marshall, E. L.; Procopiou, P. A. Chem. Commun. 1997, 155.
47. (f) Veerman, J. J. N.; van Maarseveen, J. H.; Visser, G. M.; Kruse, C. G.; Schoemaker, H. E.; Hiemstra, H.; Rutjes, F. P. J. T. Eur. J. Org. Chem. 1998, 2583.
48. (g) Grigg, R.; Sridharan, V.; York, M. Tetrahedron Lett. 1998, 39, 4139.
49. (h) Barrett, A. G. M.; Baugh, S. P. D.; Braddock, D. C.; Flack, K.; Gibson, V. C.; Giles, M. R.; Marshall, E. L.; Procopiou, P. A.; White, A. J. P.; Williams, D. J. J. Org. Chem. 1998, 63, 7893.
50. (i) Martin, S. F.; Humphrey, J. M.; Ali. A.; Hillier, M. C. J. Am. Chem. Soc. 1999, 121, 866.
51. (j) Diedrichs, N.; Westermann, B. Synlett 1999, 1127.
52. (k) Grossmith, C. E.; Senia, F.; Wagner, J. Synlett 1999, 1660.
53. (l) Tarling, C. A.; Holmes, A. B.; Markwell, R. E.; Pearson, N. D. J. Chem. Soc., Perkin Trans. 1 1999, 1695.
54. (a) References 14a and 14c.
55. (b) Martin, S. F.; Chen, H.-J.; Courtney, A. K.; Liao, Y.; Pätzel, M.; Ramser, M. N.; Wagman, A. S. Tetrahedron 1996, 52, 7251.
56. (c) White, J. D.; Hrnciar, P.; Yokochi, A. F. T. J. Am. Chem. Soc. 1998, 120, 7359.
57. (a) Visser, M. S.; Heron, N. M.; Didiuk, M. T.; Sagal, J. F.; Hoveyda, A. H. J. Am. Chem. Soc. 1996, 118, 4291.
58. (b) Fürstner, A.; Picquet, M.; Bruneau, C.; Dixneuf, P. H. Chem. Commun. 1998, 1315.
59. (c) Fürstner, A.; Hill, A. F.; Liebl, M.; Wilton-Ely, J. D. E. T. Chem Commun. 1999, 601.
60. (d) Kingsbury, J. S.; Harrity, J. P. A.; Bonitatebus, P. J., Jr.; Hoveyda, A. H. J. Am. Chem. Soc. 1999, 121, 791.
61. (e) Ackermann, L.; Fürstner, A.; Weskamp, T.; Kohl, F. J.; Herrmann, W. A. Tetrahedron Lett. 1999, 40, 4787.
62. (f) Paquette, L. A.; Leit, S. M. J. Am. Chem. Soc. 1999, 121, 8126.
63. Evans, P.; Grigg, R.; Ramzan, M. I.; Sridharan, V.; York, M. Tetrahedron Lett. 1999, 40, 3021.
64. (a) Fürstner, A.; Langemann, K. J. Am. Chem. Soc. 1997, 119, 9130.
65. (b) Fürstner, A.; Gastner, T.; Weintritt. H. J. Org. Chem. 1999, 64, 2361.
66. (c) Fürstner, A.; Siedel, G.; Kindler, N. Tetrahedron 1999, 55, 8215.
67. (a) Miller, S. J.; Kim, S.-H.; Chen Z.-R.; Grubbs, R. H. J. Am. Chem. Soc. 1995, 117, 2108.
68. (b) Fürstner, A.; Langemann, K. J. Org. Chem. 1996, 61, 8746.
69. (c) Kirkland, T. A.; Grubbs, R. H. J. Org. Chem. 1997, 62, 7310.
70. (d) Stragies, R.; Blechert, S. Synlett 1998, 169.
71. (e) Holt, D. J.; Barker, W. D.; Jenkins, P. R.; Davies, D. L.; Garrat, S.; Fawcett, J.; Russell, D. R.; Ghosh, S. Angew. Chem., Int. Ed. 1998, 37. 3298.
72. (f) Paquette, L. A.; Mendez-Andino, J. Tetrahedron Lett. 1999, 40, 4301.
73. More recently, the right-hand sector of sanglifehrin, which contains a 22-membered ring, was elaborated by RCM of a precursor that featured a diene moiety: Cabrejas, L. M. M.; Rohrbach, S.; Wagner, D.; Kallen, J.; Zenke, G.; Wagner, J. Angew. Chem., Int. Ed. 1999, 38, 2443.
74. Posner, G. H. In Asymmetric Synthesis, Volume 2: Morrison, J. D., Ed.; Academic Press: New York, 1983; Chapler 8.
75. In addition, a single report on the involvement of amines as heteronucleophiles in these processes has appeared: Matsuyama, H.; Itoh, N.; Yoshida, M.; Kamigata, N.; Sasaki, S.; Iyoda, M. Chem Lett. 1997, 375. In this study, 2-(p-tolylsulfinyl)cinnamates served as the Michael acceptors.
76. Wakui, T.; Otsuji, Y.; Imoto, E. Bull. Chem. Soc. Jpn. 1974, 47, 2267.
77. Ladlow, M.; Pattenden, G. J. Chem. Soc., Perkin Trans. 1 1988, 1107.
78. Smith, A. B., III; Branca, S. J.; Guaciaro, M. A.; Wovkulich, P. M.; Korn, A. Organic Syntheses; Wiley: New York, 1990; Collect Vol. VII, p 271.
79. Earl, R. A.; Townsend. L. B. Organic Syntheses; Wiley: New York, 1990; Collect. Vol. VII, p 334.
80. Posner, G. H.; Mallamo, J. P.; Hulce, M.; Frye, L. L. J. Am. Chem. Soc. 1982, 104, 4180.
81. Hulce, M.; Mallamo, J. P.; Frye, L. L.; Kogan, T. P.; Posner, G. H. Organic Syntheses; Wiley: New York, 1990; Collect. Vol. VII, p 495.
82. Solladié, G.; Hutt, J.; Girardin, A. Synthesis 1987, 173.
83. Nitro olefins and particularly 1-nitrocyclohexene have been shown to be particularly conducive to this type of double Michael addition/cyclization: Yakura, T.; Yamada, S.; Shima, M.; Iwamoto, M.; Ikeda, M. Chem. Pharm. Bull. 1998, 46, 744.
84. The use of potassium carbonate in refluxing THF has been shown to be effective in bringing about the condensation of acyloins with dimethyl acetylenedicarboxylate to give 4-hydroxy-4,5-dihydrofurans: Jauch, J.; Schurig, V. Tetrahedron Lett. 1991, 32, 4687.
85. Posner, G. G.; Mellamo, J. P.; Miura, K. J. Am. Chem. Soc. 1981, 103, 2886.
86. Review: Ritter, K. Synthesis 1993, 735.
87. Review: Farina, V.; Krishnamurthy, V.; Scott, W. T. Org. React. 1997, 50, 1.
88. Review: Lipshutz, B. H.; Sengupta, S. Org. React. 1992, 41, 135.
89. (a) Denny, R. W.; Nickon, A. Org. React. 1973, 20, 133.
90. (b) Wasserman, H. H.; Murray, R. W. Singlet Oxygen; Academic Press: New York, 1979.
91. Hasty, N. M.; Kearns, D. R. J. Am. Chem. Soc. 1973, 95, 3380.
92. (a) Dess, D. B.; Martin, J. C. J. Org. Chem. 1983, 48, 4155.
93. (b) Dess, D. B.; Martin, J. C. J. Am. Chem. Soc. 1991, 113, 7277.
94. (c) Ireland, R. E.; Liu, L. J. Org. Chem. 1993, 58, 2899.
95. Johnson, B. D.; Slessor, K. N.; Oehlschlager, A. C. J. Org. Chem. 1985, 50, 114.
96. Baker, K. V.; Brown, J. M.; Hughes, N.; Skarnulis, A. J.; Sexton, A. J. Org. Chem. 1991, 56, 698.