Synthesis of α-necrodol: Unexpected formation of a cyclopropene

Journal of Organic Chemistry

Volumn 62, Issue 6, 1997, Pages 1687-1690

  Taber, Douglass F ^a   Yu, Han ^a  

^a UNIVERSITY OF DELAWARE   (United States)

Author keywords

[No Author keywords available]

Indexed keywords

CYCLOPROPANE DERIVATIVE;

ARTICLE; DRUG SYNTHESIS; IN VITRO STUDY; NUCLEAR MAGNETIC RESONANCE; REACTION ANALYSIS; STEREOCHEMISTRY;

EID: 0030971175     PISSN: 00223263     EISSN: None     Source Type: Journal    
DOI: 10.1021/jo961780q     Document Type: Article

References (43)

1. For references to cyclopentene construction by intramolecular C-H insertion by an alkylidene carbene, see: (a) Karpf, M.; Dreiding, A. S. Helv. Chim. Acta 1979, 62, 825. (b) Gilbert, J. C.; Giamalva, D. H.; Weerasooriya, U. J. Org. Chem. 1983, 48, 5251. Gibert, J. C.; Giamalva, D. H.; Baze, M. E. J. Org. Chem. 1985, 50, 2557. Ochiai, M.; Kunishima, M.; Nagao, Y.; Fuji, K.; Shiro, M.; Fujita, E. J. Am. Chem. Soc. 1986, 108, 8281. (e) Gilbert, J. C.; Giamalva, D. H. J. Org. Chem. 1992, 57, 4185. (f) Ochiai, M.; Uemura, K.; Masaki, Y. J. Am. Chem. Soc. 1993, 115, 2528. (g) Schildknegt, K.; Bohnstedt, A. C.; Feldman, K. S.; Sambandam, A. J. Am. Chem. Soc 1994, 116, 93. (h) Kunishima, M.; Hioki, K.; Tani, S.; Kato, A. Tetrahedron Lett. 1994, 35, 7253. Williamson, B. L.; Tykwinski, R. R.; Stang, P. J. J. Am. Chem. Soc. 1994, 116, 93. (j) Kim, S.; Cho, C. M. Tetrahedron Lett. 1994, 35, 8405. (k) Taber, D. F.; Meagley, R. P. Tetrahedron Lett. 1994, 35, 7909. Taber, D. F.; Walter, R.; Meagley, R. P. J. Org. Chem. 1994, 59, 6014. Taber, D. F.; Sahli, A.; Yu, H.; Meagley, R. P. J. Org. Chem. 1995, 60, 6571. (n) Ohira, S.; Okai, K.; Moritani, T. J. Chem. Soc., Chem. Commun. 1995, 36, 1537. (o) Ohira, S.; Noda, I.; Mizobata, T.; Yamato, M. Tetrahedron Lett. 1995, 36, 3375. (p) Ohira S.; Sawamoto, T.; Ymato, M. Tetrahedron Lett. 1995, 36, 1537. (q) Ohira, S.; Yamasaki, K.; Nozaki, H.; Yamato, M.; Nakayama, M. Tetrhadron Lett 1995, 36, 8843. (r) Taber, D. F.; Christos, T. E.; Hodge, C. N. J. Org. Chem. 1996, 61, 2081. (s) Taber, D. F.; Meagley, R. P.; Doren, D. J. J. Org. Chem. 1996, 61, 5723.
2. For references to cyclopentene construction by intramolecular C-H insertion by an alkylidene carbene, see: (a) Karpf, M.; Dreiding, A. S. Helv. Chim. Acta 1979, 62, 825. (b) Gilbert, J. C.; Giamalva, D. H.; Weerasooriya, U. J. Org. Chem. 1983, 48, 5251. Gibert, J. C.; Giamalva, D. H.; Baze, M. E. J. Org. Chem. 1985, 50, 2557. Ochiai, M.; Kunishima, M.; Nagao, Y.; Fuji, K.; Shiro, M.; Fujita, E. J. Am. Chem. Soc. 1986, 108, 8281. (e) Gilbert, J. C.; Giamalva, D. H. J. Org. Chem. 1992, 57, 4185. (f) Ochiai, M.; Uemura, K.; Masaki, Y. J. Am. Chem. Soc. 1993, 115, 2528. (g) Schildknegt, K.; Bohnstedt, A. C.; Feldman, K. S.; Sambandam, A. J. Am. Chem. Soc 1994, 116, 93. (h) Kunishima, M.; Hioki, K.; Tani, S.; Kato, A. Tetrahedron Lett. 1994, 35, 7253. Williamson, B. L.; Tykwinski, R. R.; Stang, P. J. J. Am. Chem. Soc. 1994, 116, 93. (j) Kim, S.; Cho, C. M. Tetrahedron Lett. 1994, 35, 8405. (k) Taber, D. F.; Meagley, R. P. Tetrahedron Lett. 1994, 35, 7909. Taber, D. F.; Walter, R.; Meagley, R. P. J. Org. Chem. 1994, 59, 6014. Taber, D. F.; Sahli, A.; Yu, H.; Meagley, R. P. J. Org. Chem. 1995, 60, 6571. (n) Ohira, S.; Okai, K.; Moritani, T. J. Chem. Soc., Chem. Commun. 1995, 36, 1537. (o) Ohira, S.; Noda, I.; Mizobata, T.; Yamato, M. Tetrahedron Lett. 1995, 36, 3375. (p) Ohira S.; Sawamoto, T.; Ymato, M. Tetrahedron Lett. 1995, 36, 1537. (q) Ohira, S.; Yamasaki, K.; Nozaki, H.; Yamato, M.; Nakayama, M. Tetrhadron Lett 1995, 36, 8843. (r) Taber, D. F.; Christos, T. E.; Hodge, C. N. J. Org. Chem. 1996, 61, 2081. (s) Taber, D. F.; Meagley, R. P.; Doren, D. J. J. Org. Chem. 1996, 61, 5723.
3. For references to cyclopentene construction by intramolecular C-H insertion by an alkylidene carbene, see: (a) Karpf, M.; Dreiding, A. S. Helv. Chim. Acta 1979, 62, 825. (b) Gilbert, J. C.; Giamalva, D. H.; Weerasooriya, U. J. Org. Chem. 1983, 48, 5251. Gibert, J. C.; Giamalva, D. H.; Baze, M. E. J. Org. Chem. 1985, 50, 2557. Ochiai, M.; Kunishima, M.; Nagao, Y.; Fuji, K.; Shiro, M.; Fujita, E. J. Am. Chem. Soc. 1986, 108, 8281. (e) Gilbert, J. C.; Giamalva, D. H. J. Org. Chem. 1992, 57, 4185. (f) Ochiai, M.; Uemura, K.; Masaki, Y. J. Am. Chem. Soc. 1993, 115, 2528. (g) Schildknegt, K.; Bohnstedt, A. C.; Feldman, K. S.; Sambandam, A. J. Am. Chem. Soc 1994, 116, 93. (h) Kunishima, M.; Hioki, K.; Tani, S.; Kato, A. Tetrahedron Lett. 1994, 35, 7253. Williamson, B. L.; Tykwinski, R. R.; Stang, P. J. J. Am. Chem. Soc. 1994, 116, 93. (j) Kim, S.; Cho, C. M. Tetrahedron Lett. 1994, 35, 8405. (k) Taber, D. F.; Meagley, R. P. Tetrahedron Lett. 1994, 35, 7909. Taber, D. F.; Walter, R.; Meagley, R. P. J. Org. Chem. 1994, 59, 6014. Taber, D. F.; Sahli, A.; Yu, H.; Meagley, R. P. J. Org. Chem. 1995, 60, 6571. (n) Ohira, S.; Okai, K.; Moritani, T. J. Chem. Soc., Chem. Commun. 1995, 36, 1537. (o) Ohira, S.; Noda, I.; Mizobata, T.; Yamato, M. Tetrahedron Lett. 1995, 36, 3375. (p) Ohira S.; Sawamoto, T.; Ymato, M. Tetrahedron Lett. 1995, 36, 1537. (q) Ohira, S.; Yamasaki, K.; Nozaki, H.; Yamato, M.; Nakayama, M. Tetrhadron Lett 1995, 36, 8843. (r) Taber, D. F.; Christos, T. E.; Hodge, C. N. J. Org. Chem. 1996, 61, 2081. (s) Taber, D. F.; Meagley, R. P.; Doren, D. J. J. Org. Chem. 1996, 61, 5723.
4. For references to cyclopentene construction by intramolecular C-H insertion by an alkylidene carbene, see: (a) Karpf, M.; Dreiding, A. S. Helv. Chim. Acta 1979, 62, 825. (b) Gilbert, J. C.; Giamalva, D. H.; Weerasooriya, U. J. Org. Chem. 1983, 48, 5251. Gibert, J. C.; Giamalva, D. H.; Baze, M. E. J. Org. Chem. 1985, 50, 2557. Ochiai, M.; Kunishima, M.; Nagao, Y.; Fuji, K.; Shiro, M.; Fujita, E. J. Am. Chem. Soc. 1986, 108, 8281. (e) Gilbert, J. C.; Giamalva, D. H. J. Org. Chem. 1992, 57, 4185. (f) Ochiai, M.; Uemura, K.; Masaki, Y. J. Am. Chem. Soc. 1993, 115, 2528. (g) Schildknegt, K.; Bohnstedt, A. C.; Feldman, K. S.; Sambandam, A. J. Am. Chem. Soc 1994, 116, 93. (h) Kunishima, M.; Hioki, K.; Tani, S.; Kato, A. Tetrahedron Lett. 1994, 35, 7253. Williamson, B. L.; Tykwinski, R. R.; Stang, P. J. J. Am. Chem. Soc. 1994, 116, 93. (j) Kim, S.; Cho, C. M. Tetrahedron Lett. 1994, 35, 8405. (k) Taber, D. F.; Meagley, R. P. Tetrahedron Lett. 1994, 35, 7909. Taber, D. F.; Walter, R.; Meagley, R. P. J. Org. Chem. 1994, 59, 6014. Taber, D. F.; Sahli, A.; Yu, H.; Meagley, R. P. J. Org. Chem. 1995, 60, 6571. (n) Ohira, S.; Okai, K.; Moritani, T. J. Chem. Soc., Chem. Commun. 1995, 36, 1537. (o) Ohira, S.; Noda, I.; Mizobata, T.; Yamato, M. Tetrahedron Lett. 1995, 36, 3375. (p) Ohira S.; Sawamoto, T.; Ymato, M. Tetrahedron Lett. 1995, 36, 1537. (q) Ohira, S.; Yamasaki, K.; Nozaki, H.; Yamato, M.; Nakayama, M. Tetrhadron Lett 1995, 36, 8843. (r) Taber, D. F.; Christos, T. E.; Hodge, C. N. J. Org. Chem. 1996, 61, 2081. (s) Taber, D. F.; Meagley, R. P.; Doren, D. J. J. Org. Chem. 1996, 61, 5723.
5. For references to cyclopentene construction by intramolecular C-H insertion by an alkylidene carbene, see: (a) Karpf, M.; Dreiding, A. S. Helv. Chim. Acta 1979, 62, 825. (b) Gilbert, J. C.; Giamalva, D. H.; Weerasooriya, U. J. Org. Chem. 1983, 48, 5251. Gibert, J. C.; Giamalva, D. H.; Baze, M. E. J. Org. Chem. 1985, 50, 2557. Ochiai, M.; Kunishima, M.; Nagao, Y.; Fuji, K.; Shiro, M.; Fujita, E. J. Am. Chem. Soc. 1986, 108, 8281. (e) Gilbert, J. C.; Giamalva, D. H. J. Org. Chem. 1992, 57, 4185. (f) Ochiai, M.; Uemura, K.; Masaki, Y. J. Am. Chem. Soc. 1993, 115, 2528. (g) Schildknegt, K.; Bohnstedt, A. C.; Feldman, K. S.; Sambandam, A. J. Am. Chem. Soc 1994, 116, 93. (h) Kunishima, M.; Hioki, K.; Tani, S.; Kato, A. Tetrahedron Lett. 1994, 35, 7253. Williamson, B. L.; Tykwinski, R. R.; Stang, P. J. J. Am. Chem. Soc. 1994, 116, 93. (j) Kim, S.; Cho, C. M. Tetrahedron Lett. 1994, 35, 8405. (k) Taber, D. F.; Meagley, R. P. Tetrahedron Lett. 1994, 35, 7909. Taber, D. F.; Walter, R.; Meagley, R. P. J. Org. Chem. 1994, 59, 6014. Taber, D. F.; Sahli, A.; Yu, H.; Meagley, R. P. J. Org. Chem. 1995, 60, 6571. (n) Ohira, S.; Okai, K.; Moritani, T. J. Chem. Soc., Chem. Commun. 1995, 36, 1537. (o) Ohira, S.; Noda, I.; Mizobata, T.; Yamato, M. Tetrahedron Lett. 1995, 36, 3375. (p) Ohira S.; Sawamoto, T.; Ymato, M. Tetrahedron Lett. 1995, 36, 1537. (q) Ohira, S.; Yamasaki, K.; Nozaki, H.; Yamato, M.; Nakayama, M. Tetrhadron Lett 1995, 36, 8843. (r) Taber, D. F.; Christos, T. E.; Hodge, C. N. J. Org. Chem. 1996, 61, 2081. (s) Taber, D. F.; Meagley, R. P.; Doren, D. J. J. Org. Chem. 1996, 61, 5723.
6. For references to cyclopentene construction by intramolecular C-H insertion by an alkylidene carbene, see: (a) Karpf, M.; Dreiding, A. S. Helv. Chim. Acta 1979, 62, 825. (b) Gilbert, J. C.; Giamalva, D. H.; Weerasooriya, U. J. Org. Chem. 1983, 48, 5251. Gibert, J. C.; Giamalva, D. H.; Baze, M. E. J. Org. Chem. 1985, 50, 2557. Ochiai, M.; Kunishima, M.; Nagao, Y.; Fuji, K.; Shiro, M.; Fujita, E. J. Am. Chem. Soc. 1986, 108, 8281. (e) Gilbert, J. C.; Giamalva, D. H. J. Org. Chem. 1992, 57, 4185. (f) Ochiai, M.; Uemura, K.; Masaki, Y. J. Am. Chem. Soc. 1993, 115, 2528. (g) Schildknegt, K.; Bohnstedt, A. C.; Feldman, K. S.; Sambandam, A. J. Am. Chem. Soc 1994, 116, 93. (h) Kunishima, M.; Hioki, K.; Tani, S.; Kato, A. Tetrahedron Lett. 1994, 35, 7253. Williamson, B. L.; Tykwinski, R. R.; Stang, P. J. J. Am. Chem. Soc. 1994, 116, 93. (j) Kim, S.; Cho, C. M. Tetrahedron Lett. 1994, 35, 8405. (k) Taber, D. F.; Meagley, R. P. Tetrahedron Lett. 1994, 35, 7909. Taber, D. F.; Walter, R.; Meagley, R. P. J. Org. Chem. 1994, 59, 6014. Taber, D. F.; Sahli, A.; Yu, H.; Meagley, R. P. J. Org. Chem. 1995, 60, 6571. (n) Ohira, S.; Okai, K.; Moritani, T. J. Chem. Soc., Chem. Commun. 1995, 36, 1537. (o) Ohira, S.; Noda, I.; Mizobata, T.; Yamato, M. Tetrahedron Lett. 1995, 36, 3375. (p) Ohira S.; Sawamoto, T.; Ymato, M. Tetrahedron Lett. 1995, 36, 1537. (q) Ohira, S.; Yamasaki, K.; Nozaki, H.; Yamato, M.; Nakayama, M. Tetrhadron Lett 1995, 36, 8843. (r) Taber, D. F.; Christos, T. E.; Hodge, C. N. J. Org. Chem. 1996, 61, 2081. (s) Taber, D. F.; Meagley, R. P.; Doren, D. J. J. Org. Chem. 1996, 61, 5723.
7. For references to cyclopentene construction by intramolecular C-H insertion by an alkylidene carbene, see: (a) Karpf, M.; Dreiding, A. S. Helv. Chim. Acta 1979, 62, 825. (b) Gilbert, J. C.; Giamalva, D. H.; Weerasooriya, U. J. Org. Chem. 1983, 48, 5251. Gibert, J. C.; Giamalva, D. H.; Baze, M. E. J. Org. Chem. 1985, 50, 2557. Ochiai, M.; Kunishima, M.; Nagao, Y.; Fuji, K.; Shiro, M.; Fujita, E. J. Am. Chem. Soc. 1986, 108, 8281. (e) Gilbert, J. C.; Giamalva, D. H. J. Org. Chem. 1992, 57, 4185. (f) Ochiai, M.; Uemura, K.; Masaki, Y. J. Am. Chem. Soc. 1993, 115, 2528. (g) Schildknegt, K.; Bohnstedt, A. C.; Feldman, K. S.; Sambandam, A. J. Am. Chem. Soc 1994, 116, 93. (h) Kunishima, M.; Hioki, K.; Tani, S.; Kato, A. Tetrahedron Lett. 1994, 35, 7253. Williamson, B. L.; Tykwinski, R. R.; Stang, P. J. J. Am. Chem. Soc. 1994, 116, 93. (j) Kim, S.; Cho, C. M. Tetrahedron Lett. 1994, 35, 8405. (k) Taber, D. F.; Meagley, R. P. Tetrahedron Lett. 1994, 35, 7909. Taber, D. F.; Walter, R.; Meagley, R. P. J. Org. Chem. 1994, 59, 6014. Taber, D. F.; Sahli, A.; Yu, H.; Meagley, R. P. J. Org. Chem. 1995, 60, 6571. (n) Ohira, S.; Okai, K.; Moritani, T. J. Chem. Soc., Chem. Commun. 1995, 36, 1537. (o) Ohira, S.; Noda, I.; Mizobata, T.; Yamato, M. Tetrahedron Lett. 1995, 36, 3375. (p) Ohira S.; Sawamoto, T.; Ymato, M. Tetrahedron Lett. 1995, 36, 1537. (q) Ohira, S.; Yamasaki, K.; Nozaki, H.; Yamato, M.; Nakayama, M. Tetrhadron Lett 1995, 36, 8843. (r) Taber, D. F.; Christos, T. E.; Hodge, C. N. J. Org. Chem. 1996, 61, 2081. (s) Taber, D. F.; Meagley, R. P.; Doren, D. J. J. Org. Chem. 1996, 61, 5723.
8. For references to cyclopentene construction by intramolecular C-H insertion by an alkylidene carbene, see: (a) Karpf, M.; Dreiding, A. S. Helv. Chim. Acta 1979, 62, 825. (b) Gilbert, J. C.; Giamalva, D. H.; Weerasooriya, U. J. Org. Chem. 1983, 48, 5251. Gibert, J. C.; Giamalva, D. H.; Baze, M. E. J. Org. Chem. 1985, 50, 2557. Ochiai, M.; Kunishima, M.; Nagao, Y.; Fuji, K.; Shiro, M.; Fujita, E. J. Am. Chem. Soc. 1986, 108, 8281. (e) Gilbert, J. C.; Giamalva, D. H. J. Org. Chem. 1992, 57, 4185. (f) Ochiai, M.; Uemura, K.; Masaki, Y. J. Am. Chem. Soc. 1993, 115, 2528. (g) Schildknegt, K.; Bohnstedt, A. C.; Feldman, K. S.; Sambandam, A. J. Am. Chem. Soc 1994, 116, 93. (h) Kunishima, M.; Hioki, K.; Tani, S.; Kato, A. Tetrahedron Lett. 1994, 35, 7253. Williamson, B. L.; Tykwinski, R. R.; Stang, P. J. J. Am. Chem. Soc. 1994, 116, 93. (j) Kim, S.; Cho, C. M. Tetrahedron Lett. 1994, 35, 8405. (k) Taber, D. F.; Meagley, R. P. Tetrahedron Lett. 1994, 35, 7909. Taber, D. F.; Walter, R.; Meagley, R. P. J. Org. Chem. 1994, 59, 6014. Taber, D. F.; Sahli, A.; Yu, H.; Meagley, R. P. J. Org. Chem. 1995, 60, 6571. (n) Ohira, S.; Okai, K.; Moritani, T. J. Chem. Soc., Chem. Commun. 1995, 36, 1537. (o) Ohira, S.; Noda, I.; Mizobata, T.; Yamato, M. Tetrahedron Lett. 1995, 36, 3375. (p) Ohira S.; Sawamoto, T.; Ymato, M. Tetrahedron Lett. 1995, 36, 1537. (q) Ohira, S.; Yamasaki, K.; Nozaki, H.; Yamato, M.; Nakayama, M. Tetrhadron Lett 1995, 36, 8843. (r) Taber, D. F.; Christos, T. E.; Hodge, C. N. J. Org. Chem. 1996, 61, 2081. (s) Taber, D. F.; Meagley, R. P.; Doren, D. J. J. Org. Chem. 1996, 61, 5723.
9. For references to cyclopentene construction by intramolecular C-H insertion by an alkylidene carbene, see: (a) Karpf, M.; Dreiding, A. S. Helv. Chim. Acta 1979, 62, 825. (b) Gilbert, J. C.; Giamalva, D. H.; Weerasooriya, U. J. Org. Chem. 1983, 48, 5251. Gibert, J. C.; Giamalva, D. H.; Baze, M. E. J. Org. Chem. 1985, 50, 2557. Ochiai, M.; Kunishima, M.; Nagao, Y.; Fuji, K.; Shiro, M.; Fujita, E. J. Am. Chem. Soc. 1986, 108, 8281. (e) Gilbert, J. C.; Giamalva, D. H. J. Org. Chem. 1992, 57, 4185. (f) Ochiai, M.; Uemura, K.; Masaki, Y. J. Am. Chem. Soc. 1993, 115, 2528. (g) Schildknegt, K.; Bohnstedt, A. C.; Feldman, K. S.; Sambandam, A. J. Am. Chem. Soc 1994, 116, 93. (h) Kunishima, M.; Hioki, K.; Tani, S.; Kato, A. Tetrahedron Lett. 1994, 35, 7253. Williamson, B. L.; Tykwinski, R. R.; Stang, P. J. J. Am. Chem. Soc. 1994, 116, 93. (j) Kim, S.; Cho, C. M. Tetrahedron Lett. 1994, 35, 8405. (k) Taber, D. F.; Meagley, R. P. Tetrahedron Lett. 1994, 35, 7909. Taber, D. F.; Walter, R.; Meagley, R. P. J. Org. Chem. 1994, 59, 6014. Taber, D. F.; Sahli, A.; Yu, H.; Meagley, R. P. J. Org. Chem. 1995, 60, 6571. (n) Ohira, S.; Okai, K.; Moritani, T. J. Chem. Soc., Chem. Commun. 1995, 36, 1537. (o) Ohira, S.; Noda, I.; Mizobata, T.; Yamato, M. Tetrahedron Lett. 1995, 36, 3375. (p) Ohira S.; Sawamoto, T.; Ymato, M. Tetrahedron Lett. 1995, 36, 1537. (q) Ohira, S.; Yamasaki, K.; Nozaki, H.; Yamato, M.; Nakayama, M. Tetrhadron Lett 1995, 36, 8843. (r) Taber, D. F.; Christos, T. E.; Hodge, C. N. J. Org. Chem. 1996, 61, 2081. (s) Taber, D. F.; Meagley, R. P.; Doren, D. J. J. Org. Chem. 1996, 61, 5723.
10. For references to cyclopentene construction by intramolecular C-H insertion by an alkylidene carbene, see: (a) Karpf, M.; Dreiding, A. S. Helv. Chim. Acta 1979, 62, 825. (b) Gilbert, J. C.; Giamalva, D. H.; Weerasooriya, U. J. Org. Chem. 1983, 48, 5251. Gibert, J. C.; Giamalva, D. H.; Baze, M. E. J. Org. Chem. 1985, 50, 2557. Ochiai, M.; Kunishima, M.; Nagao, Y.; Fuji, K.; Shiro, M.; Fujita, E. J. Am. Chem. Soc. 1986, 108, 8281. (e) Gilbert, J. C.; Giamalva, D. H. J. Org. Chem. 1992, 57, 4185. (f) Ochiai, M.; Uemura, K.; Masaki, Y. J. Am. Chem. Soc. 1993, 115, 2528. (g) Schildknegt, K.; Bohnstedt, A. C.; Feldman, K. S.; Sambandam, A. J. Am. Chem. Soc 1994, 116, 93. (h) Kunishima, M.; Hioki, K.; Tani, S.; Kato, A. Tetrahedron Lett. 1994, 35, 7253. Williamson, B. L.; Tykwinski, R. R.; Stang, P. J. J. Am. Chem. Soc. 1994, 116, 93. (j) Kim, S.; Cho, C. M. Tetrahedron Lett. 1994, 35, 8405. (k) Taber, D. F.; Meagley, R. P. Tetrahedron Lett. 1994, 35, 7909. Taber, D. F.; Walter, R.; Meagley, R. P. J. Org. Chem. 1994, 59, 6014. Taber, D. F.; Sahli, A.; Yu, H.; Meagley, R. P. J. Org. Chem. 1995, 60, 6571. (n) Ohira, S.; Okai, K.; Moritani, T. J. Chem. Soc., Chem. Commun. 1995, 36, 1537. (o) Ohira, S.; Noda, I.; Mizobata, T.; Yamato, M. Tetrahedron Lett. 1995, 36, 3375. (p) Ohira S.; Sawamoto, T.; Ymato, M. Tetrahedron Lett. 1995, 36, 1537. (q) Ohira, S.; Yamasaki, K.; Nozaki, H.; Yamato, M.; Nakayama, M. Tetrhadron Lett 1995, 36, 8843. (r) Taber, D. F.; Christos, T. E.; Hodge, C. N. J. Org. Chem. 1996, 61, 2081. (s) Taber, D. F.; Meagley, R. P.; Doren, D. J. J. Org. Chem. 1996, 61, 5723.
11. For references to cyclopentene construction by intramolecular C-H insertion by an alkylidene carbene, see: (a) Karpf, M.; Dreiding, A. S. Helv. Chim. Acta 1979, 62, 825. (b) Gilbert, J. C.; Giamalva, D. H.; Weerasooriya, U. J. Org. Chem. 1983, 48, 5251. Gibert, J. C.; Giamalva, D. H.; Baze, M. E. J. Org. Chem. 1985, 50, 2557. Ochiai, M.; Kunishima, M.; Nagao, Y.; Fuji, K.; Shiro, M.; Fujita, E. J. Am. Chem. Soc. 1986, 108, 8281. (e) Gilbert, J. C.; Giamalva, D. H. J. Org. Chem. 1992, 57, 4185. (f) Ochiai, M.; Uemura, K.; Masaki, Y. J. Am. Chem. Soc. 1993, 115, 2528. (g) Schildknegt, K.; Bohnstedt, A. C.; Feldman, K. S.; Sambandam, A. J. Am. Chem. Soc 1994, 116, 93. (h) Kunishima, M.; Hioki, K.; Tani, S.; Kato, A. Tetrahedron Lett. 1994, 35, 7253. Williamson, B. L.; Tykwinski, R. R.; Stang, P. J. J. Am. Chem. Soc. 1994, 116, 93. (j) Kim, S.; Cho, C. M. Tetrahedron Lett. 1994, 35, 8405. (k) Taber, D. F.; Meagley, R. P. Tetrahedron Lett. 1994, 35, 7909. Taber, D. F.; Walter, R.; Meagley, R. P. J. Org. Chem. 1994, 59, 6014. Taber, D. F.; Sahli, A.; Yu, H.; Meagley, R. P. J. Org. Chem. 1995, 60, 6571. (n) Ohira, S.; Okai, K.; Moritani, T. J. Chem. Soc., Chem. Commun. 1995, 36, 1537. (o) Ohira, S.; Noda, I.; Mizobata, T.; Yamato, M. Tetrahedron Lett. 1995, 36, 3375. (p) Ohira S.; Sawamoto, T.; Ymato, M. Tetrahedron Lett. 1995, 36, 1537. (q) Ohira, S.; Yamasaki, K.; Nozaki, H.; Yamato, M.; Nakayama, M. Tetrhadron Lett 1995, 36, 8843. (r) Taber, D. F.; Christos, T. E.; Hodge, C. N. J. Org. Chem. 1996, 61, 2081. (s) Taber, D. F.; Meagley, R. P.; Doren, D. J. J. Org. Chem. 1996, 61, 5723.
12. For references to cyclopentene construction by intramolecular C-H insertion by an alkylidene carbene, see: (a) Karpf, M.; Dreiding, A. S. Helv. Chim. Acta 1979, 62, 825. (b) Gilbert, J. C.; Giamalva, D. H.; Weerasooriya, U. J. Org. Chem. 1983, 48, 5251. Gibert, J. C.; Giamalva, D. H.; Baze, M. E. J. Org. Chem. 1985, 50, 2557. Ochiai, M.; Kunishima, M.; Nagao, Y.; Fuji, K.; Shiro, M.; Fujita, E. J. Am. Chem. Soc. 1986, 108, 8281. (e) Gilbert, J. C.; Giamalva, D. H. J. Org. Chem. 1992, 57, 4185. (f) Ochiai, M.; Uemura, K.; Masaki, Y. J. Am. Chem. Soc. 1993, 115, 2528. (g) Schildknegt, K.; Bohnstedt, A. C.; Feldman, K. S.; Sambandam, A. J. Am. Chem. Soc 1994, 116, 93. (h) Kunishima, M.; Hioki, K.; Tani, S.; Kato, A. Tetrahedron Lett. 1994, 35, 7253. Williamson, B. L.; Tykwinski, R. R.; Stang, P. J. J. Am. Chem. Soc. 1994, 116, 93. (j) Kim, S.; Cho, C. M. Tetrahedron Lett. 1994, 35, 8405. (k) Taber, D. F.; Meagley, R. P. Tetrahedron Lett. 1994, 35, 7909. Taber, D. F.; Walter, R.; Meagley, R. P. J. Org. Chem. 1994, 59, 6014. Taber, D. F.; Sahli, A.; Yu, H.; Meagley, R. P. J. Org. Chem. 1995, 60, 6571. (n) Ohira, S.; Okai, K.; Moritani, T. J. Chem. Soc., Chem. Commun. 1995, 36, 1537. (o) Ohira, S.; Noda, I.; Mizobata, T.; Yamato, M. Tetrahedron Lett. 1995, 36, 3375. (p) Ohira S.; Sawamoto, T.; Ymato, M. Tetrahedron Lett. 1995, 36, 1537. (q) Ohira, S.; Yamasaki, K.; Nozaki, H.; Yamato, M.; Nakayama, M. Tetrhadron Lett 1995, 36, 8843. (r) Taber, D. F.; Christos, T. E.; Hodge, C. N. J. Org. Chem. 1996, 61, 2081. (s) Taber, D. F.; Meagley, R. P.; Doren, D. J. J. Org. Chem. 1996, 61, 5723.
13. For references to cyclopentene construction by intramolecular C-H insertion by an alkylidene carbene, see: (a) Karpf, M.; Dreiding, A. S. Helv. Chim. Acta 1979, 62, 825. (b) Gilbert, J. C.; Giamalva, D. H.; Weerasooriya, U. J. Org. Chem. 1983, 48, 5251. Gibert, J. C.; Giamalva, D. H.; Baze, M. E. J. Org. Chem. 1985, 50, 2557. Ochiai, M.; Kunishima, M.; Nagao, Y.; Fuji, K.; Shiro, M.; Fujita, E. J. Am. Chem. Soc. 1986, 108, 8281. (e) Gilbert, J. C.; Giamalva, D. H. J. Org. Chem. 1992, 57, 4185. (f) Ochiai, M.; Uemura, K.; Masaki, Y. J. Am. Chem. Soc. 1993, 115, 2528. (g) Schildknegt, K.; Bohnstedt, A. C.; Feldman, K. S.; Sambandam, A. J. Am. Chem. Soc 1994, 116, 93. (h) Kunishima, M.; Hioki, K.; Tani, S.; Kato, A. Tetrahedron Lett. 1994, 35, 7253. Williamson, B. L.; Tykwinski, R. R.; Stang, P. J. J. Am. Chem. Soc. 1994, 116, 93. (j) Kim, S.; Cho, C. M. Tetrahedron Lett. 1994, 35, 8405. (k) Taber, D. F.; Meagley, R. P. Tetrahedron Lett. 1994, 35, 7909. Taber, D. F.; Walter, R.; Meagley, R. P. J. Org. Chem. 1994, 59, 6014. Taber, D. F.; Sahli, A.; Yu, H.; Meagley, R. P. J. Org. Chem. 1995, 60, 6571. (n) Ohira, S.; Okai, K.; Moritani, T. J. Chem. Soc., Chem. Commun. 1995, 36, 1537. (o) Ohira, S.; Noda, I.; Mizobata, T.; Yamato, M. Tetrahedron Lett. 1995, 36, 3375. (p) Ohira S.; Sawamoto, T.; Ymato, M. Tetrahedron Lett. 1995, 36, 1537. (q) Ohira, S.; Yamasaki, K.; Nozaki, H.; Yamato, M.; Nakayama, M. Tetrhadron Lett 1995, 36, 8843. (r) Taber, D. F.; Christos, T. E.; Hodge, C. N. J. Org. Chem. 1996, 61, 2081. (s) Taber, D. F.; Meagley, R. P.; Doren, D. J. J. Org. Chem. 1996, 61, 5723.
14. For references to cyclopentene construction by intramolecular C-H insertion by an alkylidene carbene, see: (a) Karpf, M.; Dreiding, A. S. Helv. Chim. Acta 1979, 62, 825. (b) Gilbert, J. C.; Giamalva, D. H.; Weerasooriya, U. J. Org. Chem. 1983, 48, 5251. Gibert, J. C.; Giamalva, D. H.; Baze, M. E. J. Org. Chem. 1985, 50, 2557. Ochiai, M.; Kunishima, M.; Nagao, Y.; Fuji, K.; Shiro, M.; Fujita, E. J. Am. Chem. Soc. 1986, 108, 8281. (e) Gilbert, J. C.; Giamalva, D. H. J. Org. Chem. 1992, 57, 4185. (f) Ochiai, M.; Uemura, K.; Masaki, Y. J. Am. Chem. Soc. 1993, 115, 2528. (g) Schildknegt, K.; Bohnstedt, A. C.; Feldman, K. S.; Sambandam, A. J. Am. Chem. Soc 1994, 116, 93. (h) Kunishima, M.; Hioki, K.; Tani, S.; Kato, A. Tetrahedron Lett. 1994, 35, 7253. Williamson, B. L.; Tykwinski, R. R.; Stang, P. J. J. Am. Chem. Soc. 1994, 116, 93. (j) Kim, S.; Cho, C. M. Tetrahedron Lett. 1994, 35, 8405. (k) Taber, D. F.; Meagley, R. P. Tetrahedron Lett. 1994, 35, 7909. Taber, D. F.; Walter, R.; Meagley, R. P. J. Org. Chem. 1994, 59, 6014. Taber, D. F.; Sahli, A.; Yu, H.; Meagley, R. P. J. Org. Chem. 1995, 60, 6571. (n) Ohira, S.; Okai, K.; Moritani, T. J. Chem. Soc., Chem. Commun. 1995, 36, 1537. (o) Ohira, S.; Noda, I.; Mizobata, T.; Yamato, M. Tetrahedron Lett. 1995, 36, 3375. (p) Ohira S.; Sawamoto, T.; Ymato, M. Tetrahedron Lett. 1995, 36, 1537. (q) Ohira, S.; Yamasaki, K.; Nozaki, H.; Yamato, M.; Nakayama, M. Tetrhadron Lett 1995, 36, 8843. (r) Taber, D. F.; Christos, T. E.; Hodge, C. N. J. Org. Chem. 1996, 61, 2081. (s) Taber, D. F.; Meagley, R. P.; Doren, D. J. J. Org. Chem. 1996, 61, 5723.
15. For references to cyclopentene construction by intramolecular C-H insertion by an alkylidene carbene, see: (a) Karpf, M.; Dreiding, A. S. Helv. Chim. Acta 1979, 62, 825. (b) Gilbert, J. C.; Giamalva, D. H.; Weerasooriya, U. J. Org. Chem. 1983, 48, 5251. Gibert, J. C.; Giamalva, D. H.; Baze, M. E. J. Org. Chem. 1985, 50, 2557. Ochiai, M.; Kunishima, M.; Nagao, Y.; Fuji, K.; Shiro, M.; Fujita, E. J. Am. Chem. Soc. 1986, 108, 8281. (e) Gilbert, J. C.; Giamalva, D. H. J. Org. Chem. 1992, 57, 4185. (f) Ochiai, M.; Uemura, K.; Masaki, Y. J. Am. Chem. Soc. 1993, 115, 2528. (g) Schildknegt, K.; Bohnstedt, A. C.; Feldman, K. S.; Sambandam, A. J. Am. Chem. Soc 1994, 116, 93. (h) Kunishima, M.; Hioki, K.; Tani, S.; Kato, A. Tetrahedron Lett. 1994, 35, 7253. Williamson, B. L.; Tykwinski, R. R.; Stang, P. J. J. Am. Chem. Soc. 1994, 116, 93. (j) Kim, S.; Cho, C. M. Tetrahedron Lett. 1994, 35, 8405. (k) Taber, D. F.; Meagley, R. P. Tetrahedron Lett. 1994, 35, 7909. Taber, D. F.; Walter, R.; Meagley, R. P. J. Org. Chem. 1994, 59, 6014. Taber, D. F.; Sahli, A.; Yu, H.; Meagley, R. P. J. Org. Chem. 1995, 60, 6571. (n) Ohira, S.; Okai, K.; Moritani, T. J. Chem. Soc., Chem. Commun. 1995, 36, 1537. (o) Ohira, S.; Noda, I.; Mizobata, T.; Yamato, M. Tetrahedron Lett. 1995, 36, 3375. (p) Ohira S.; Sawamoto, T.; Ymato, M. Tetrahedron Lett. 1995, 36, 1537. (q) Ohira, S.; Yamasaki, K.; Nozaki, H.; Yamato, M.; Nakayama, M. Tetrhadron Lett 1995, 36, 8843. (r) Taber, D. F.; Christos, T. E.; Hodge, C. N. J. Org. Chem. 1996, 61, 2081. (s) Taber, D. F.; Meagley, R. P.; Doren, D. J. J. Org. Chem. 1996, 61, 5723.
16. For references to cyclopentene construction by intramolecular C-H insertion by an alkylidene carbene, see: (a) Karpf, M.; Dreiding, A. S. Helv. Chim. Acta 1979, 62, 825. (b) Gilbert, J. C.; Giamalva, D. H.; Weerasooriya, U. J. Org. Chem. 1983, 48, 5251. Gibert, J. C.; Giamalva, D. H.; Baze, M. E. J. Org. Chem. 1985, 50, 2557. Ochiai, M.; Kunishima, M.; Nagao, Y.; Fuji, K.; Shiro, M.; Fujita, E. J. Am. Chem. Soc. 1986, 108, 8281. (e) Gilbert, J. C.; Giamalva, D. H. J. Org. Chem. 1992, 57, 4185. (f) Ochiai, M.; Uemura, K.; Masaki, Y. J. Am. Chem. Soc. 1993, 115, 2528. (g) Schildknegt, K.; Bohnstedt, A. C.; Feldman, K. S.; Sambandam, A. J. Am. Chem. Soc 1994, 116, 93. (h) Kunishima, M.; Hioki, K.; Tani, S.; Kato, A. Tetrahedron Lett. 1994, 35, 7253. Williamson, B. L.; Tykwinski, R. R.; Stang, P. J. J. Am. Chem. Soc. 1994, 116, 93. (j) Kim, S.; Cho, C. M. Tetrahedron Lett. 1994, 35, 8405. (k) Taber, D. F.; Meagley, R. P. Tetrahedron Lett. 1994, 35, 7909. Taber, D. F.; Walter, R.; Meagley, R. P. J. Org. Chem. 1994, 59, 6014. Taber, D. F.; Sahli, A.; Yu, H.; Meagley, R. P. J. Org. Chem. 1995, 60, 6571. (n) Ohira, S.; Okai, K.; Moritani, T. J. Chem. Soc., Chem. Commun. 1995, 36, 1537. (o) Ohira, S.; Noda, I.; Mizobata, T.; Yamato, M. Tetrahedron Lett. 1995, 36, 3375. (p) Ohira S.; Sawamoto, T.; Ymato, M. Tetrahedron Lett. 1995, 36, 1537. (q) Ohira, S.; Yamasaki, K.; Nozaki, H.; Yamato, M.; Nakayama, M. Tetrhadron Lett 1995, 36, 8843. (r) Taber, D. F.; Christos, T. E.; Hodge, C. N. J. Org. Chem. 1996, 61, 2081. (s) Taber, D. F.; Meagley, R. P.; Doren, D. J. J. Org. Chem. 1996, 61, 5723.
17. For references to cyclopentene construction by intramolecular C-H insertion by an alkylidene carbene, see: (a) Karpf, M.; Dreiding, A. S. Helv. Chim. Acta 1979, 62, 825. (b) Gilbert, J. C.; Giamalva, D. H.; Weerasooriya, U. J. Org. Chem. 1983, 48, 5251. Gibert, J. C.; Giamalva, D. H.; Baze, M. E. J. Org. Chem. 1985, 50, 2557. Ochiai, M.; Kunishima, M.; Nagao, Y.; Fuji, K.; Shiro, M.; Fujita, E. J. Am. Chem. Soc. 1986, 108, 8281. (e) Gilbert, J. C.; Giamalva, D. H. J. Org. Chem. 1992, 57, 4185. (f) Ochiai, M.; Uemura, K.; Masaki, Y. J. Am. Chem. Soc. 1993, 115, 2528. (g) Schildknegt, K.; Bohnstedt, A. C.; Feldman, K. S.; Sambandam, A. J. Am. Chem. Soc 1994, 116, 93. (h) Kunishima, M.; Hioki, K.; Tani, S.; Kato, A. Tetrahedron Lett. 1994, 35, 7253. Williamson, B. L.; Tykwinski, R. R.; Stang, P. J. J. Am. Chem. Soc. 1994, 116, 93. (j) Kim, S.; Cho, C. M. Tetrahedron Lett. 1994, 35, 8405. (k) Taber, D. F.; Meagley, R. P. Tetrahedron Lett. 1994, 35, 7909. Taber, D. F.; Walter, R.; Meagley, R. P. J. Org. Chem. 1994, 59, 6014. Taber, D. F.; Sahli, A.; Yu, H.; Meagley, R. P. J. Org. Chem. 1995, 60, 6571. (n) Ohira, S.; Okai, K.; Moritani, T. J. Chem. Soc., Chem. Commun. 1995, 36, 1537. (o) Ohira, S.; Noda, I.; Mizobata, T.; Yamato, M. Tetrahedron Lett. 1995, 36, 3375. (p) Ohira S.; Sawamoto, T.; Ymato, M. Tetrahedron Lett. 1995, 36, 1537. (q) Ohira, S.; Yamasaki, K.; Nozaki, H.; Yamato, M.; Nakayama, M. Tetrhadron Lett 1995, 36, 8843. (r) Taber, D. F.; Christos, T. E.; Hodge, C. N. J. Org. Chem. 1996, 61, 2081. (s) Taber, D. F.; Meagley, R. P.; Doren, D. J. J. Org. Chem. 1996, 61, 5723.
18. For references to cyclopentene construction by intramolecular C-H insertion by an alkylidene carbene, see: (a) Karpf, M.; Dreiding, A. S. Helv. Chim. Acta 1979, 62, 825. (b) Gilbert, J. C.; Giamalva, D. H.; Weerasooriya, U. J. Org. Chem. 1983, 48, 5251. Gibert, J. C.; Giamalva, D. H.; Baze, M. E. J. Org. Chem. 1985, 50, 2557. Ochiai, M.; Kunishima, M.; Nagao, Y.; Fuji, K.; Shiro, M.; Fujita, E. J. Am. Chem. Soc. 1986, 108, 8281. (e) Gilbert, J. C.; Giamalva, D. H. J. Org. Chem. 1992, 57, 4185. (f) Ochiai, M.; Uemura, K.; Masaki, Y. J. Am. Chem. Soc. 1993, 115, 2528. (g) Schildknegt, K.; Bohnstedt, A. C.; Feldman, K. S.; Sambandam, A. J. Am. Chem. Soc 1994, 116, 93. (h) Kunishima, M.; Hioki, K.; Tani, S.; Kato, A. Tetrahedron Lett. 1994, 35, 7253. Williamson, B. L.; Tykwinski, R. R.; Stang, P. J. J. Am. Chem. Soc. 1994, 116, 93. (j) Kim, S.; Cho, C. M. Tetrahedron Lett. 1994, 35, 8405. (k) Taber, D. F.; Meagley, R. P. Tetrahedron Lett. 1994, 35, 7909. Taber, D. F.; Walter, R.; Meagley, R. P. J. Org. Chem. 1994, 59, 6014. Taber, D. F.; Sahli, A.; Yu, H.; Meagley, R. P. J. Org. Chem. 1995, 60, 6571. (n) Ohira, S.; Okai, K.; Moritani, T. J. Chem. Soc., Chem. Commun. 1995, 36, 1537. (o) Ohira, S.; Noda, I.; Mizobata, T.; Yamato, M. Tetrahedron Lett. 1995, 36, 3375. (p) Ohira S.; Sawamoto, T.; Ymato, M. Tetrahedron Lett. 1995, 36, 1537. (q) Ohira, S.; Yamasaki, K.; Nozaki, H.; Yamato, M.; Nakayama, M. Tetrhadron Lett 1995, 36, 8843. (r) Taber, D. F.; Christos, T. E.; Hodge, C. N. J. Org. Chem. 1996, 61, 2081. (s) Taber, D. F.; Meagley, R. P.; Doren, D. J. J. Org. Chem. 1996, 61, 5723.
19. For references to cyclopentene construction by intramolecular C-H insertion by an alkylidene carbene, see: (a) Karpf, M.; Dreiding, A. S. Helv. Chim. Acta 1979, 62, 825. (b) Gilbert, J. C.; Giamalva, D. H.; Weerasooriya, U. J. Org. Chem. 1983, 48, 5251. Gibert, J. C.; Giamalva, D. H.; Baze, M. E. J. Org. Chem. 1985, 50, 2557. Ochiai, M.; Kunishima, M.; Nagao, Y.; Fuji, K.; Shiro, M.; Fujita, E. J. Am. Chem. Soc. 1986, 108, 8281. (e) Gilbert, J. C.; Giamalva, D. H. J. Org. Chem. 1992, 57, 4185. (f) Ochiai, M.; Uemura, K.; Masaki, Y. J. Am. Chem. Soc. 1993, 115, 2528. (g) Schildknegt, K.; Bohnstedt, A. C.; Feldman, K. S.; Sambandam, A. J. Am. Chem. Soc 1994, 116, 93. (h) Kunishima, M.; Hioki, K.; Tani, S.; Kato, A. Tetrahedron Lett. 1994, 35, 7253. Williamson, B. L.; Tykwinski, R. R.; Stang, P. J. J. Am. Chem. Soc. 1994, 116, 93. (j) Kim, S.; Cho, C. M. Tetrahedron Lett. 1994, 35, 8405. (k) Taber, D. F.; Meagley, R. P. Tetrahedron Lett. 1994, 35, 7909. Taber, D. F.; Walter, R.; Meagley, R. P. J. Org. Chem. 1994, 59, 6014. Taber, D. F.; Sahli, A.; Yu, H.; Meagley, R. P. J. Org. Chem. 1995, 60, 6571. (n) Ohira, S.; Okai, K.; Moritani, T. J. Chem. Soc., Chem. Commun. 1995, 36, 1537. (o) Ohira, S.; Noda, I.; Mizobata, T.; Yamato, M. Tetrahedron Lett. 1995, 36, 3375. (p) Ohira S.; Sawamoto, T.; Ymato, M. Tetrahedron Lett. 1995, 36, 1537. (q) Ohira, S.; Yamasaki, K.; Nozaki, H.; Yamato, M.; Nakayama, M. Tetrhadron Lett 1995, 36, 8843. (r) Taber, D. F.; Christos, T. E.; Hodge, C. N. J. Org. Chem. 1996, 61, 2081. (s) Taber, D. F.; Meagley, R. P.; Doren, D. J. J. Org. Chem. 1996, 61, 5723.
20. (a) Eisner, T.; Meinwald, J. Psyche 1982, 89, 357.
21. (b) Eisner, T.; Deyrup, M.; Jacobs, R.; Meinwald, J. J. Chem. Ecol. 1986, 12, 1407.
22. Meinwald, J. Ann. N. Y. Acad. Sci. 1986, 471, 197.
23. Roach, B.; Eisner, T.; Meinwald, J. J. Org. Chem. 1990, 55, 4047.
24. Jacobs, R. T.; Feutrill, G. I.; Meinwald, J. J. Org. Chem. 1990, 55, 4051.
25. For the references to the syntheses of β-necrodol and epi-β-necrodol, see: (a) Oppolzer, W.; Schneider, P. Helv. Chim. Acta 1986, 69, 1817. (b) Trost, B. M.; Braslau, R. Tetrahedron Lett. 1988, 29, 1231. Schulte-Elte, K. H.; Pamingle, H. Helv. Chim. Acta 1989, 72, 1158.
26. For the references to the syntheses of β-necrodol and epi-β-necrodol, see: (a) Oppolzer, W.; Schneider, P. Helv. Chim. Acta 1986, 69, 1817. (b) Trost, B. M.; Braslau, R. Tetrahedron Lett. 1988, 29, 1231. Schulte-Elte, K. H.; Pamingle, H. Helv. Chim. Acta 1989, 72, 1158.
27. For the references to the syntheses of β-necrodol and epi-β-necrodol, see: (a) Oppolzer, W.; Schneider, P. Helv. Chim. Acta 1986, 69, 1817. (b) Trost, B. M.; Braslau, R. Tetrahedron Lett. 1988, 29, 1231. Schulte-Elte, K. H.; Pamingle, H. Helv. Chim. Acta 1989, 72, 1158.
28. Stork, G.; Nakatani, K. Tetrahedron Lett. 1988, 29, 2283.
29. For an RHF approximation of the insertion transition state, see our Web site at "http://valhalla.chem.udel.edu/alkylidene.html". The lead graphic in this document depicts the calculated orbital overlap in the C-H insertion transition state. The RHF approximation is also available electronically (see the Supporting Information).
30. (a) Molecular mechanics calculations were carried out using the program Mechanics, implemented on a Tektronix CAChe workstation interfaced with a Silicon Graphics Indigo workstation. This code is based on the MM2 molecular mechanics code of Allinger, with extensions provided by the CAChe group. Full documentation is available from Oxford Molecular, Beaverton, OR. (c) For a detailed analysis of the electronic structure of alkylidenes (vinylidenes) and of the rearrangement to the corresponding alkyne, see: Gallo, M. M.; Hamilton, T. P.; Schaefer, H. F., III. J. Am. Chem. Soc. 1990, 112, 8714.
31. Manusco, A. J.; Huang, S. L.; Swern, D. J. J. Org. Chem. 1978, 43, 2480.
32. Ikeda, I.; Machii, Y.; Okahara, M. Synthesis 1978, 301.
33. Almost any monosubstituted epoxide should work in this procedure. The original authors used ethylene oxide and propylene oxide.
34. Edstrom, E.; Livinghouse, T. J. Chem. Soc., Chem. Commun. 1986, 279.
35. Weiberth, F. J.; Hall, S. S. J. Org. Chem. 1987, 52, 3901.
36. 1H NMR spectrum of the crude product mixture.
37. For leading references to cyclopropene construction, see: (a) Likhotvorik, I. R.; Brown, D. W.; Jones, M. J. Am. Chem. Soc. 1994, 116, 6175. (b) Boese, R.; Blaser, D.; Billups, W. E.; Haley, M. M.; Luo, W.; Arney, B. E. J. Org. Chem. 1995, 59, 8125. Baldwin, J. E.; Villarica, K. A. J. Org. Chem. 1995, 60, 186. Kurek-Tyrlik, A.; Minksztym, K.; Wicha, J. J. Am. Chem. Soc. 1995, 117, 1849.
38. For leading references to cyclopropene construction, see: (a) Likhotvorik, I. R.; Brown, D. W.; Jones, M. J. Am. Chem. Soc. 1994, 116, 6175. (b) Boese, R.; Blaser, D.; Billups, W. E.; Haley, M. M.; Luo, W.; Arney, B. E. J. Org. Chem. 1995, 59, 8125. Baldwin, J. E.; Villarica, K. A. J. Org. Chem. 1995, 60, 186. Kurek-Tyrlik, A.; Minksztym, K.; Wicha, J. J. Am. Chem. Soc. 1995, 117, 1849.
39. For leading references to cyclopropene construction, see: (a) Likhotvorik, I. R.; Brown, D. W.; Jones, M. J. Am. Chem. Soc. 1994, 116, 6175. (b) Boese, R.; Blaser, D.; Billups, W. E.; Haley, M. M.; Luo, W.; Arney, B. E. J. Org. Chem. 1995, 59, 8125. Baldwin, J. E.; Villarica, K. A. J. Org. Chem. 1995, 60, 186. Kurek-Tyrlik, A.; Minksztym, K.; Wicha, J. J. Am. Chem. Soc. 1995, 117, 1849.
40. For leading references to cyclopropene construction, see: (a) Likhotvorik, I. R.; Brown, D. W.; Jones, M. J. Am. Chem. Soc. 1994, 116, 6175. (b) Boese, R.; Blaser, D.; Billups, W. E.; Haley, M. M.; Luo, W.; Arney, B. E. J. Org. Chem. 1995, 59, 8125. Baldwin, J. E.; Villarica, K. A. J. Org. Chem. 1995, 60, 186. Kurek-Tyrlik, A.; Minksztym, K.; Wicha, J. J. Am. Chem. Soc. 1995, 117, 1849.
41. 13C spectrum in this area, we were unable to confirm this signal for 8.
42. 13C signals of terminal alkynes also are "up". Again, the C-H coupling constant in this case is large, 230 Hz.
43. For general experimental procedures, see: Taber, D. F.; Houze, J. B. J. Org. Chem. 1994, 59, 4004.