Intramolecular [4+3] cycloadditions. Towards a synthesis of widdrol

Heterocycles

Volumn 62, Issue , 2004, Pages 583-618

  Harmata, Michael ^a   Kahraman, Mehmet ^a   Adenu, Gilbert ^a   Barnes, Charles L ^a  

^a UNIVERSITY OF MISSOURI   (United States)

Author keywords

[No Author keywords available]

Indexed keywords

ALLYL COMPOUND; CATION; FURAN; LEWIS ACID; SESQUITERPENE; SULFONE; UNCLASSIFIED DRUG; VINYLTHIONIUM ION; WIDDROL;

ALKYLATION; ARTICLE; CYCLOADDITION; REACTION ANALYSIS; SYNTHESIS;

EID: 0347720689     PISSN: 03855414     EISSN: None     Source Type: Journal    
DOI: 10.3987/COM-03-S(P)53     Document Type: Article

References (80)

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11. For some examples of the use of vinylthionium ions in synthesis, see: R. Hunter and C. D. Simon, Tetrahedron Lett., 1986, 27, 1385; R. Hunter and C. D. Simon, Tetrahedron Lett., 1988, 29, 2257; R. Hunter, L. Carlton, P. F. Cirillo, J. P. Michael, C. D. Simon, and D. S. Walter, J. Chem. Soc., Perkin Trans. I, 1989, 1631; R. Hunter, J. P. Michael, C. D. Simon, and D. S. Walter, Tetrahedron, 1994, 50, 9365; R. Hunter, J. P. Michael, and D. S Walter, Tetrahedron Lett., 1992, 33, 5413; R. Hunter, J. P. Michael, and D. S. Walter, Tetrahedron, 1994, 50, 9377; R. Hunter, J. P. Michael, and D. S. Walter, Tetrahedron Lett., 1994, 35, 5481; Y. Hashimoto and T. Mukaiyama, Chem Lett., 1986, 755; Y. Hashimoto and T. Mukaiyama, Chem. Lett., 1986, 1623; Y. Hashimoto, H. Sugumi, T. Okauchi, and T. Mukaiyama, Chem. Lett., 1987, 1691; Y. Hashimoto, H. Sugumi, T. Okauchi, and T. Mukaiyama, Chem. Lett., 1987, 1695; T. Ishihara, T. Shinozaki, and M. Kuroboshi, Chem. Lett., 1989, 1369; R. Brückner and R. Huisgen, J. Org. Chem., 1991, 56, 1677; M. Keiichi, K. Domon, K. Tanino, and I. Kuwajima, Synlett, 1996, 157; Y. Takahashi, K. Tanino, and I. Kuwajima, Tetrahedron Lett., 1996, 37, 5943; K. Domon, K. Masuya, K. Tanino, and I. Kuwajima, Tetrahedron Lett., 1997, 38, 465; T. F. Braish, J. C. Saddler, and P. L. Fuchs, J. Org. Chem., 1988, 53, 3647.
12. For some examples of the use of vinylthionium ions in synthesis, see: R. Hunter and C. D. Simon, Tetrahedron Lett., 1986, 27, 1385; R. Hunter and C. D. Simon, Tetrahedron Lett., 1988, 29, 2257; R. Hunter, L. Carlton, P. F. Cirillo, J. P. Michael, C. D. Simon, and D. S. Walter, J. Chem. Soc., Perkin Trans. I, 1989, 1631; R. Hunter, J. P. Michael, C. D. Simon, and D. S. Walter, Tetrahedron, 1994, 50, 9365; R. Hunter, J. P. Michael, and D. S Walter, Tetrahedron Lett., 1992, 33, 5413; R. Hunter, J. P. Michael, and D. S. Walter, Tetrahedron, 1994, 50, 9377; R. Hunter, J. P. Michael, and D. S. Walter, Tetrahedron Lett., 1994, 35, 5481; Y. Hashimoto and T. Mukaiyama, Chem Lett., 1986, 755; Y. Hashimoto and T. Mukaiyama, Chem. Lett., 1986, 1623; Y. Hashimoto, H. Sugumi, T. Okauchi, and T. Mukaiyama, Chem. Lett., 1987, 1691; Y. Hashimoto, H. Sugumi, T. Okauchi, and T. Mukaiyama, Chem. Lett., 1987, 1695; T. Ishihara, T. Shinozaki, and M. Kuroboshi, Chem. Lett., 1989, 1369; R. Brückner and R. Huisgen, J. Org. Chem., 1991, 56, 1677; M. Keiichi, K. Domon, K. Tanino, and I. Kuwajima, Synlett, 1996, 157; Y. Takahashi, K. Tanino, and I. Kuwajima, Tetrahedron Lett., 1996, 37, 5943; K. Domon, K. Masuya, K. Tanino, and I. Kuwajima, Tetrahedron Lett., 1997, 38, 465; T. F. Braish, J. C. Saddler, and P. L. Fuchs, J. Org. Chem., 1988, 53, 3647.
13. For some examples of the use of vinylthionium ions in synthesis, see: R. Hunter and C. D. Simon, Tetrahedron Lett., 1986, 27, 1385; R. Hunter and C. D. Simon, Tetrahedron Lett., 1988, 29, 2257; R. Hunter, L. Carlton, P. F. Cirillo, J. P. Michael, C. D. Simon, and D. S. Walter, J. Chem. Soc., Perkin Trans. I, 1989, 1631; R. Hunter, J. P. Michael, C. D. Simon, and D. S. Walter, Tetrahedron, 1994, 50, 9365; R. Hunter, J. P. Michael, and D. S Walter, Tetrahedron Lett., 1992, 33, 5413; R. Hunter, J. P. Michael, and D. S. Walter, Tetrahedron, 1994, 50, 9377; R. Hunter, J. P. Michael, and D. S. Walter, Tetrahedron Lett., 1994, 35, 5481; Y. Hashimoto and T. Mukaiyama, Chem Lett., 1986, 755; Y. Hashimoto and T. Mukaiyama, Chem. Lett., 1986, 1623; Y. Hashimoto, H. Sugumi, T. Okauchi, and T. Mukaiyama, Chem. Lett., 1987, 1691; Y. Hashimoto, H. Sugumi, T. Okauchi, and T. Mukaiyama, Chem. Lett., 1987, 1695; T. Ishihara, T. Shinozaki, and M. Kuroboshi, Chem. Lett., 1989, 1369; R. Brückner and R. Huisgen, J. Org. Chem., 1991, 56, 1677; M. Keiichi, K. Domon, K. Tanino, and I. Kuwajima, Synlett, 1996, 157; Y. Takahashi, K. Tanino, and I. Kuwajima, Tetrahedron Lett., 1996, 37, 5943; K. Domon, K. Masuya, K. Tanino, and I. Kuwajima, Tetrahedron Lett., 1997, 38, 465; T. F. Braish, J. C. Saddler, and P. L. Fuchs, J. Org. Chem., 1988, 53, 3647.
14. For some examples of the use of vinylthionium ions in synthesis, see: R. Hunter and C. D. Simon, Tetrahedron Lett., 1986, 27, 1385; R. Hunter and C. D. Simon, Tetrahedron Lett., 1988, 29, 2257; R. Hunter, L. Carlton, P. F. Cirillo, J. P. Michael, C. D. Simon, and D. S. Walter, J. Chem. Soc., Perkin Trans. I, 1989, 1631; R. Hunter, J. P. Michael, C. D. Simon, and D. S. Walter, Tetrahedron, 1994, 50, 9365; R. Hunter, J. P. Michael, and D. S Walter, Tetrahedron Lett., 1992, 33, 5413; R. Hunter, J. P. Michael, and D. S. Walter, Tetrahedron, 1994, 50, 9377; R. Hunter, J. P. Michael, and D. S. Walter, Tetrahedron Lett., 1994, 35, 5481; Y. Hashimoto and T. Mukaiyama, Chem Lett., 1986, 755; Y. Hashimoto and T. Mukaiyama, Chem. Lett., 1986, 1623; Y. Hashimoto, H. Sugumi, T. Okauchi, and T. Mukaiyama, Chem. Lett., 1987, 1691; Y. Hashimoto, H. Sugumi, T. Okauchi, and T. Mukaiyama, Chem. Lett., 1987, 1695; T. Ishihara, T. Shinozaki, and M. Kuroboshi, Chem. Lett., 1989, 1369; R. Brückner and R. Huisgen, J. Org. Chem., 1991, 56, 1677; M. Keiichi, K. Domon, K. Tanino, and I. Kuwajima, Synlett, 1996, 157; Y. Takahashi, K. Tanino, and I. Kuwajima, Tetrahedron Lett., 1996, 37, 5943; K. Domon, K. Masuya, K. Tanino, and I. Kuwajima, Tetrahedron Lett., 1997, 38, 465; T. F. Braish, J. C. Saddler, and P. L. Fuchs, J. Org. Chem., 1988, 53, 3647.
15. For some examples of the use of vinylthionium ions in synthesis, see: R. Hunter and C. D. Simon, Tetrahedron Lett., 1986, 27, 1385; R. Hunter and C. D. Simon, Tetrahedron Lett., 1988, 29, 2257; R. Hunter, L. Carlton, P. F. Cirillo, J. P. Michael, C. D. Simon, and D. S. Walter, J. Chem. Soc., Perkin Trans. I, 1989, 1631; R. Hunter, J. P. Michael, C. D. Simon, and D. S. Walter, Tetrahedron, 1994, 50, 9365; R. Hunter, J. P. Michael, and D. S Walter, Tetrahedron Lett., 1992, 33, 5413; R. Hunter, J. P. Michael, and D. S. Walter, Tetrahedron, 1994, 50, 9377; R. Hunter, J. P. Michael, and D. S. Walter, Tetrahedron Lett., 1994, 35, 5481; Y. Hashimoto and T. Mukaiyama, Chem Lett., 1986, 755; Y. Hashimoto and T. Mukaiyama, Chem. Lett., 1986, 1623; Y. Hashimoto, H. Sugumi, T. Okauchi, and T. Mukaiyama, Chem. Lett., 1987, 1691; Y. Hashimoto, H. Sugumi, T. Okauchi, and T. Mukaiyama, Chem. Lett., 1987, 1695; T. Ishihara, T. Shinozaki, and M. Kuroboshi, Chem. Lett., 1989, 1369; R. Brückner and R. Huisgen, J. Org. Chem., 1991, 56, 1677; M. Keiichi, K. Domon, K. Tanino, and I. Kuwajima, Synlett, 1996, 157; Y. Takahashi, K. Tanino, and I. Kuwajima, Tetrahedron Lett., 1996, 37, 5943; K. Domon, K. Masuya, K. Tanino, and I. Kuwajima, Tetrahedron Lett., 1997, 38, 465; T. F. Braish, J. C. Saddler, and P. L. Fuchs, J. Org. Chem., 1988, 53, 3647.
16. For some examples of the use of vinylthionium ions in synthesis, see: R. Hunter and C. D. Simon, Tetrahedron Lett., 1986, 27, 1385; R. Hunter and C. D. Simon, Tetrahedron Lett., 1988, 29, 2257; R. Hunter, L. Carlton, P. F. Cirillo, J. P. Michael, C. D. Simon, and D. S. Walter, J. Chem. Soc., Perkin Trans. I, 1989, 1631; R. Hunter, J. P. Michael, C. D. Simon, and D. S. Walter, Tetrahedron, 1994, 50, 9365; R. Hunter, J. P. Michael, and D. S Walter, Tetrahedron Lett., 1992, 33, 5413; R. Hunter, J. P. Michael, and D. S. Walter, Tetrahedron, 1994, 50, 9377; R. Hunter, J. P. Michael, and D. S. Walter, Tetrahedron Lett., 1994, 35, 5481; Y. Hashimoto and T. Mukaiyama, Chem Lett., 1986, 755; Y. Hashimoto and T. Mukaiyama, Chem. Lett., 1986, 1623; Y. Hashimoto, H. Sugumi, T. Okauchi, and T. Mukaiyama, Chem. Lett., 1987, 1691; Y. Hashimoto, H. Sugumi, T. Okauchi, and T. Mukaiyama, Chem. Lett., 1987, 1695; T. Ishihara, T. Shinozaki, and M. Kuroboshi, Chem. Lett., 1989, 1369; R. Brückner and R. Huisgen, J. Org. Chem., 1991, 56, 1677; M. Keiichi, K. Domon, K. Tanino, and I. Kuwajima, Synlett, 1996, 157; Y. Takahashi, K. Tanino, and I. Kuwajima, Tetrahedron Lett., 1996, 37, 5943; K. Domon, K. Masuya, K. Tanino, and I. Kuwajima, Tetrahedron Lett., 1997, 38, 465; T. F. Braish, J. C. Saddler, and P. L. Fuchs, J. Org. Chem., 1988, 53, 3647.
17. For some examples of the use of vinylthionium ions in synthesis, see: R. Hunter and C. D. Simon, Tetrahedron Lett., 1986, 27, 1385; R. Hunter and C. D. Simon, Tetrahedron Lett., 1988, 29, 2257; R. Hunter, L. Carlton, P. F. Cirillo, J. P. Michael, C. D. Simon, and D. S. Walter, J. Chem. Soc., Perkin Trans. I, 1989, 1631; R. Hunter, J. P. Michael, C. D. Simon, and D. S. Walter, Tetrahedron, 1994, 50, 9365; R. Hunter, J. P. Michael, and D. S Walter, Tetrahedron Lett., 1992, 33, 5413; R. Hunter, J. P. Michael, and D. S. Walter, Tetrahedron, 1994, 50, 9377; R. Hunter, J. P. Michael, and D. S. Walter, Tetrahedron Lett., 1994, 35, 5481; Y. Hashimoto and T. Mukaiyama, Chem Lett., 1986, 755; Y. Hashimoto and T. Mukaiyama, Chem. Lett., 1986, 1623; Y. Hashimoto, H. Sugumi, T. Okauchi, and T. Mukaiyama, Chem. Lett., 1987, 1691; Y. Hashimoto, H. Sugumi, T. Okauchi, and T. Mukaiyama, Chem. Lett., 1987, 1695; T. Ishihara, T. Shinozaki, and M. Kuroboshi, Chem. Lett., 1989, 1369; R. Brückner and R. Huisgen, J. Org. Chem., 1991, 56, 1677; M. Keiichi, K. Domon, K. Tanino, and I. Kuwajima, Synlett, 1996, 157; Y. Takahashi, K. Tanino, and I. Kuwajima, Tetrahedron Lett., 1996, 37, 5943; K. Domon, K. Masuya, K. Tanino, and I. Kuwajima, Tetrahedron Lett., 1997, 38, 465; T. F. Braish, J. C. Saddler, and P. L. Fuchs, J. Org. Chem., 1988, 53, 3647.
18. For some examples of the use of vinylthionium ions in synthesis, see: R. Hunter and C. D. Simon, Tetrahedron Lett., 1986, 27, 1385; R. Hunter and C. D. Simon, Tetrahedron Lett., 1988, 29, 2257; R. Hunter, L. Carlton, P. F. Cirillo, J. P. Michael, C. D. Simon, and D. S. Walter, J. Chem. Soc., Perkin Trans. I, 1989, 1631; R. Hunter, J. P. Michael, C. D. Simon, and D. S. Walter, Tetrahedron, 1994, 50, 9365; R. Hunter, J. P. Michael, and D. S Walter, Tetrahedron Lett., 1992, 33, 5413; R. Hunter, J. P. Michael, and D. S. Walter, Tetrahedron, 1994, 50, 9377; R. Hunter, J. P. Michael, and D. S. Walter, Tetrahedron Lett., 1994, 35, 5481; Y. Hashimoto and T. Mukaiyama, Chem Lett., 1986, 755; Y. Hashimoto and T. Mukaiyama, Chem. Lett., 1986, 1623; Y. Hashimoto, H. Sugumi, T. Okauchi, and T. Mukaiyama, Chem. Lett., 1987, 1691; Y. Hashimoto, H. Sugumi, T. Okauchi, and T. Mukaiyama, Chem. Lett., 1987, 1695; T. Ishihara, T. Shinozaki, and M. Kuroboshi, Chem. Lett., 1989, 1369; R. Brückner and R. Huisgen, J. Org. Chem., 1991, 56, 1677; M. Keiichi, K. Domon, K. Tanino, and I. Kuwajima, Synlett, 1996, 157; Y. Takahashi, K. Tanino, and I. Kuwajima, Tetrahedron Lett., 1996, 37, 5943; K. Domon, K. Masuya, K. Tanino, and I. Kuwajima, Tetrahedron Lett., 1997, 38, 465; T. F. Braish, J. C. Saddler, and P. L. Fuchs, J. Org. Chem., 1988, 53, 3647.
19. For some examples of the use of vinylthionium ions in synthesis, see: R. Hunter and C. D. Simon, Tetrahedron Lett., 1986, 27, 1385; R. Hunter and C. D. Simon, Tetrahedron Lett., 1988, 29, 2257; R. Hunter, L. Carlton, P. F. Cirillo, J. P. Michael, C. D. Simon, and D. S. Walter, J. Chem. Soc., Perkin Trans. I, 1989, 1631; R. Hunter, J. P. Michael, C. D. Simon, and D. S. Walter, Tetrahedron, 1994, 50, 9365; R. Hunter, J. P. Michael, and D. S Walter, Tetrahedron Lett., 1992, 33, 5413; R. Hunter, J. P. Michael, and D. S. Walter, Tetrahedron, 1994, 50, 9377; R. Hunter, J. P. Michael, and D. S. Walter, Tetrahedron Lett., 1994, 35, 5481; Y. Hashimoto and T. Mukaiyama, Chem Lett., 1986, 755; Y. Hashimoto and T. Mukaiyama, Chem. Lett., 1986, 1623; Y. Hashimoto, H. Sugumi, T. Okauchi, and T. Mukaiyama, Chem. Lett., 1987, 1691; Y. Hashimoto, H. Sugumi, T. Okauchi, and T. Mukaiyama, Chem. Lett., 1987, 1695; T. Ishihara, T. Shinozaki, and M. Kuroboshi, Chem. Lett., 1989, 1369; R. Brückner and R. Huisgen, J. Org. Chem., 1991, 56, 1677; M. Keiichi, K. Domon, K. Tanino, and I. Kuwajima, Synlett, 1996, 157; Y. Takahashi, K. Tanino, and I. Kuwajima, Tetrahedron Lett., 1996, 37, 5943; K. Domon, K. Masuya, K. Tanino, and I. Kuwajima, Tetrahedron Lett., 1997, 38, 465; T. F. Braish, J. C. Saddler, and P. L. Fuchs, J. Org. Chem., 1988, 53, 3647.
20. For some examples of the use of vinylthionium ions in synthesis, see: R. Hunter and C. D. Simon, Tetrahedron Lett., 1986, 27, 1385; R. Hunter and C. D. Simon, Tetrahedron Lett., 1988, 29, 2257; R. Hunter, L. Carlton, P. F. Cirillo, J. P. Michael, C. D. Simon, and D. S. Walter, J. Chem. Soc., Perkin Trans. I, 1989, 1631; R. Hunter, J. P. Michael, C. D. Simon, and D. S. Walter, Tetrahedron, 1994, 50, 9365; R. Hunter, J. P. Michael, and D. S Walter, Tetrahedron Lett., 1992, 33, 5413; R. Hunter, J. P. Michael, and D. S. Walter, Tetrahedron, 1994, 50, 9377; R. Hunter, J. P. Michael, and D. S. Walter, Tetrahedron Lett., 1994, 35, 5481; Y. Hashimoto and T. Mukaiyama, Chem Lett., 1986, 755; Y. Hashimoto and T. Mukaiyama, Chem. Lett., 1986, 1623; Y. Hashimoto, H. Sugumi, T. Okauchi, and T. Mukaiyama, Chem. Lett., 1987, 1691; Y. Hashimoto, H. Sugumi, T. Okauchi, and T. Mukaiyama, Chem. Lett., 1987, 1695; T. Ishihara, T. Shinozaki, and M. Kuroboshi, Chem. Lett., 1989, 1369; R. Brückner and R. Huisgen, J. Org. Chem., 1991, 56, 1677; M. Keiichi, K. Domon, K. Tanino, and I. Kuwajima, Synlett, 1996, 157; Y. Takahashi, K. Tanino, and I. Kuwajima, Tetrahedron Lett., 1996, 37, 5943; K. Domon, K. Masuya, K. Tanino, and I. Kuwajima, Tetrahedron Lett., 1997, 38, 465; T. F. Braish, J. C. Saddler, and P. L. Fuchs, J. Org. Chem., 1988, 53, 3647.
21. For some examples of the use of vinylthionium ions in synthesis, see: R. Hunter and C. D. Simon, Tetrahedron Lett., 1986, 27, 1385; R. Hunter and C. D. Simon, Tetrahedron Lett., 1988, 29, 2257; R. Hunter, L. Carlton, P. F. Cirillo, J. P. Michael, C. D. Simon, and D. S. Walter, J. Chem. Soc., Perkin Trans. I, 1989, 1631; R. Hunter, J. P. Michael, C. D. Simon, and D. S. Walter, Tetrahedron, 1994, 50, 9365; R. Hunter, J. P. Michael, and D. S Walter, Tetrahedron Lett., 1992, 33, 5413; R. Hunter, J. P. Michael, and D. S. Walter, Tetrahedron, 1994, 50, 9377; R. Hunter, J. P. Michael, and D. S. Walter, Tetrahedron Lett., 1994, 35, 5481; Y. Hashimoto and T. Mukaiyama, Chem Lett., 1986, 755; Y. Hashimoto and T. Mukaiyama, Chem. Lett., 1986, 1623; Y. Hashimoto, H. Sugumi, T. Okauchi, and T. Mukaiyama, Chem. Lett., 1987, 1691; Y. Hashimoto, H. Sugumi, T. Okauchi, and T. Mukaiyama, Chem. Lett., 1987, 1695; T. Ishihara, T. Shinozaki, and M. Kuroboshi, Chem. Lett., 1989, 1369; R. Brückner and R. Huisgen, J. Org. Chem., 1991, 56, 1677; M. Keiichi, K. Domon, K. Tanino, and I. Kuwajima, Synlett, 1996, 157; Y. Takahashi, K. Tanino, and I. Kuwajima, Tetrahedron Lett., 1996, 37, 5943; K. Domon, K. Masuya, K. Tanino, and I. Kuwajima, Tetrahedron Lett., 1997, 38, 465; T. F. Braish, J. C. Saddler, and P. L. Fuchs, J. Org. Chem., 1988, 53, 3647.
22. For some examples of the use of vinylthionium ions in synthesis, see: R. Hunter and C. D. Simon, Tetrahedron Lett., 1986, 27, 1385; R. Hunter and C. D. Simon, Tetrahedron Lett., 1988, 29, 2257; R. Hunter, L. Carlton, P. F. Cirillo, J. P. Michael, C. D. Simon, and D. S. Walter, J. Chem. Soc., Perkin Trans. I, 1989, 1631; R. Hunter, J. P. Michael, C. D. Simon, and D. S. Walter, Tetrahedron, 1994, 50, 9365; R. Hunter, J. P. Michael, and D. S Walter, Tetrahedron Lett., 1992, 33, 5413; R. Hunter, J. P. Michael, and D. S. Walter, Tetrahedron, 1994, 50, 9377; R. Hunter, J. P. Michael, and D. S. Walter, Tetrahedron Lett., 1994, 35, 5481; Y. Hashimoto and T. Mukaiyama, Chem Lett., 1986, 755; Y. Hashimoto and T. Mukaiyama, Chem. Lett., 1986, 1623; Y. Hashimoto, H. Sugumi, T. Okauchi, and T. Mukaiyama, Chem. Lett., 1987, 1691; Y. Hashimoto, H. Sugumi, T. Okauchi, and T. Mukaiyama, Chem. Lett., 1987, 1695; T. Ishihara, T. Shinozaki, and M. Kuroboshi, Chem. Lett., 1989, 1369; R. Brückner and R. Huisgen, J. Org. Chem., 1991, 56, 1677; M. Keiichi, K. Domon, K. Tanino, and I. Kuwajima, Synlett, 1996, 157; Y. Takahashi, K. Tanino, and I. Kuwajima, Tetrahedron Lett., 1996, 37, 5943; K. Domon, K. Masuya, K. Tanino, and I. Kuwajima, Tetrahedron Lett., 1997, 38, 465; T. F. Braish, J. C. Saddler, and P. L. Fuchs, J. Org. Chem., 1988, 53, 3647.
23. For some examples of the use of vinylthionium ions in synthesis, see: R. Hunter and C. D. Simon, Tetrahedron Lett., 1986, 27, 1385; R. Hunter and C. D. Simon, Tetrahedron Lett., 1988, 29, 2257; R. Hunter, L. Carlton, P. F. Cirillo, J. P. Michael, C. D. Simon, and D. S. Walter, J. Chem. Soc., Perkin Trans. I, 1989, 1631; R. Hunter, J. P. Michael, C. D. Simon, and D. S. Walter, Tetrahedron, 1994, 50, 9365; R. Hunter, J. P. Michael, and D. S Walter, Tetrahedron Lett., 1992, 33, 5413; R. Hunter, J. P. Michael, and D. S. Walter, Tetrahedron, 1994, 50, 9377; R. Hunter, J. P. Michael, and D. S. Walter, Tetrahedron Lett., 1994, 35, 5481; Y. Hashimoto and T. Mukaiyama, Chem Lett., 1986, 755; Y. Hashimoto and T. Mukaiyama, Chem. Lett., 1986, 1623; Y. Hashimoto, H. Sugumi, T. Okauchi, and T. Mukaiyama, Chem. Lett., 1987, 1691; Y. Hashimoto, H. Sugumi, T. Okauchi, and T. Mukaiyama, Chem. Lett., 1987, 1695; T. Ishihara, T. Shinozaki, and M. Kuroboshi, Chem. Lett., 1989, 1369; R. Brückner and R. Huisgen, J. Org. Chem., 1991, 56, 1677; M. Keiichi, K. Domon, K. Tanino, and I. Kuwajima, Synlett, 1996, 157; Y. Takahashi, K. Tanino, and I. Kuwajima, Tetrahedron Lett., 1996, 37, 5943; K. Domon, K. Masuya, K. Tanino, and I. Kuwajima, Tetrahedron Lett., 1997, 38, 465; T. F. Braish, J. C. Saddler, and P. L. Fuchs, J. Org. Chem., 1988, 53, 3647.
24. For some examples of the use of vinylthionium ions in synthesis, see: R. Hunter and C. D. Simon, Tetrahedron Lett., 1986, 27, 1385; R. Hunter and C. D. Simon, Tetrahedron Lett., 1988, 29, 2257; R. Hunter, L. Carlton, P. F. Cirillo, J. P. Michael, C. D. Simon, and D. S. Walter, J. Chem. Soc., Perkin Trans. I, 1989, 1631; R. Hunter, J. P. Michael, C. D. Simon, and D. S. Walter, Tetrahedron, 1994, 50, 9365; R. Hunter, J. P. Michael, and D. S Walter, Tetrahedron Lett., 1992, 33, 5413; R. Hunter, J. P. Michael, and D. S. Walter, Tetrahedron, 1994, 50, 9377; R. Hunter, J. P. Michael, and D. S. Walter, Tetrahedron Lett., 1994, 35, 5481; Y. Hashimoto and T. Mukaiyama, Chem Lett., 1986, 755; Y. Hashimoto and T. Mukaiyama, Chem. Lett., 1986, 1623; Y. Hashimoto, H. Sugumi, T. Okauchi, and T. Mukaiyama, Chem. Lett., 1987, 1691; Y. Hashimoto, H. Sugumi, T. Okauchi, and T. Mukaiyama, Chem. Lett., 1987, 1695; T. Ishihara, T. Shinozaki, and M. Kuroboshi, Chem. Lett., 1989, 1369; R. Brückner and R. Huisgen, J. Org. Chem., 1991, 56, 1677; M. Keiichi, K. Domon, K. Tanino, and I. Kuwajima, Synlett, 1996, 157; Y. Takahashi, K. Tanino, and I. Kuwajima, Tetrahedron Lett., 1996, 37, 5943; K. Domon, K. Masuya, K. Tanino, and I. Kuwajima, Tetrahedron Lett., 1997, 38, 465; T. F. Braish, J. C. Saddler, and P. L. Fuchs, J. Org. Chem., 1988, 53, 3647.
25. For some examples of the use of vinylthionium ions in synthesis, see: R. Hunter and C. D. Simon, Tetrahedron Lett., 1986, 27, 1385; R. Hunter and C. D. Simon, Tetrahedron Lett., 1988, 29, 2257; R. Hunter, L. Carlton, P. F. Cirillo, J. P. Michael, C. D. Simon, and D. S. Walter, J. Chem. Soc., Perkin Trans. I, 1989, 1631; R. Hunter, J. P. Michael, C. D. Simon, and D. S. Walter, Tetrahedron, 1994, 50, 9365; R. Hunter, J. P. Michael, and D. S Walter, Tetrahedron Lett., 1992, 33, 5413; R. Hunter, J. P. Michael, and D. S. Walter, Tetrahedron, 1994, 50, 9377; R. Hunter, J. P. Michael, and D. S. Walter, Tetrahedron Lett., 1994, 35, 5481; Y. Hashimoto and T. Mukaiyama, Chem Lett., 1986, 755; Y. Hashimoto and T. Mukaiyama, Chem. Lett., 1986, 1623; Y. Hashimoto, H. Sugumi, T. Okauchi, and T. Mukaiyama, Chem. Lett., 1987, 1691; Y. Hashimoto, H. Sugumi, T. Okauchi, and T. Mukaiyama, Chem. Lett., 1987, 1695; T. Ishihara, T. Shinozaki, and M. Kuroboshi, Chem. Lett., 1989, 1369; R. Brückner and R. Huisgen, J. Org. Chem., 1991, 56, 1677; M. Keiichi, K. Domon, K. Tanino, and I. Kuwajima, Synlett, 1996, 157; Y. Takahashi, K. Tanino, and I. Kuwajima, Tetrahedron Lett., 1996, 37, 5943; K. Domon, K. Masuya, K. Tanino, and I. Kuwajima, Tetrahedron Lett., 1997, 38, 465; T. F. Braish, J. C. Saddler, and P. L. Fuchs, J. Org. Chem., 1988, 53, 3647.
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61. For some examples of oxabicyclic ring opening, see: S. Woo and B. A. Keay, Synthesis, 1996, 669; M. Lautens and P. Chiu, Tetrahedron Lett., 1991, 32, 4827; M. Lautens, P. Chiu, S. Ma, and T. Rovis, J. Am. Chem. Soc., 1995, 117, 532; M. Lautens, Pure and Appl. Chem., 1992, 64, 1873; M. Lautens, Synlett, 1993, 177; M. Lautens, P. Chiu, and J. T. Colucci, Angew. Chem., Int. Ed. Engl., 1993, 32, 281; S. Woo and B. A. Keay, Tetrahedron Lett., 1992, 33, 2661; G. A. Molander and P. R. Eastwood, J. Org. Chem., 1995, 60, 4559; M. Lautens and P. Chiu, Tetrahedron Lett., 1991, 32, 4827; J. H. Rigby and J. A. Z. Wilson, J. Org. Chem., 1987, 52, 34.
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63. For some examples of oxabicyclic ring opening, see: S. Woo and B. A. Keay, Synthesis, 1996, 669; M. Lautens and P. Chiu, Tetrahedron Lett., 1991, 32, 4827; M. Lautens, P. Chiu, S. Ma, and T. Rovis, J. Am. Chem. Soc., 1995, 117, 532; M. Lautens, Pure and Appl. Chem., 1992, 64, 1873; M. Lautens, Synlett, 1993, 177; M. Lautens, P. Chiu, and J. T. Colucci, Angew. Chem., Int. Ed. Engl., 1993, 32, 281; S. Woo and B. A. Keay, Tetrahedron Lett., 1992, 33, 2661; G. A. Molander and P. R. Eastwood, J. Org. Chem., 1995, 60, 4559; M. Lautens and P. Chiu, Tetrahedron Lett., 1991, 32, 4827; J. H. Rigby and J. A. Z. Wilson, J. Org. Chem., 1987, 52, 34.
64. For some examples of oxabicyclic ring opening, see: S. Woo and B. A. Keay, Synthesis, 1996, 669; M. Lautens and P. Chiu, Tetrahedron Lett., 1991, 32, 4827; M. Lautens, P. Chiu, S. Ma, and T. Rovis, J. Am. Chem. Soc., 1995, 117, 532; M. Lautens, Pure and Appl. Chem., 1992, 64, 1873; M. Lautens, Synlett, 1993, 177; M. Lautens, P. Chiu, and J. T. Colucci, Angew. Chem., Int. Ed. Engl., 1993, 32, 281; S. Woo and B. A. Keay, Tetrahedron Lett., 1992, 33, 2661; G. A. Molander and P. R. Eastwood, J. Org. Chem., 1995, 60, 4559; M. Lautens and P. Chiu, Tetrahedron Lett., 1991, 32, 4827; J. H. Rigby and J. A. Z. Wilson, J. Org. Chem., 1987, 52, 34.
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