Reactivity of Mitsunobu reagent toward carbonyl compounds

Organic Letters

Volumn 7, Issue 3, 2005, Pages 495-498

  Otte, Ryan D ^a   Sakata, Tomoyo ^a   Guzei, Ilia A ^a   Lee, Daesung ^a  

^a UNIVERSITY OF WISCONSIN MADISON   (United States)

Author keywords

[No Author keywords available]

Indexed keywords

CARBON; CARBONYL DERIVATIVE; CARBOXYLIC ACID DERIVATIVE; NITROGEN DERIVATIVE; TRIPHENYLPHOSPHINE;

ARTICLE; CHEMICAL REACTION; CHEMICAL STRUCTURE; MITSUNOBU REACTION;

ALCOHOLS; INDICATORS AND REAGENTS; KETONES; MODELS, MOLECULAR; MOLECULAR CONFORMATION;

EID: 13844276146     PISSN: 15237060     EISSN: None     Source Type: Journal    
DOI: 10.1021/ol0475008     Document Type: Article

References (35)

1. Reviews: (a) Mitsunobu, O. Synthesis 1981, 1. (b) Hughes, D. L. Org. Prep. Proced. Int. 1996, 28, 127. Mechanistic studies (c) Hughes, D. L. Org. React. 1992, 42, 335. (d) Camp, D.; Jenkins, I. D. J. Org. Chem. 1989, 54, 3045. (e) Camp, D.; Jenkins, I. D. J. Org. Chem. 1989, 54, 3049. (f) Wilson, S. R.; Perez, J.; Pasternak, A. J. Am. Chem. Soc. 1993, 115, 1994. (g) Hughes, D. L.; Reamer, R. A. J. Org. Chem. 1996, 61, 2967. (h) Watanabe, T.; Gridnev, I. D.; Imamoto, T. Chirality 2000, 12, 346. (i) Ahn, C.; Correia, R.; DeShong, P. J. Org. Chem. 2002, 67, 1751. (j) McNulty, J.; Capretta, A.; Laritchev, V.; Dyck, J.; Robertson, A. J. Angew. Chem., Int. Ed. 2003, 42, 4051. (k) Dinsmore C. J.; Mercer, S. P. Org. Lett. 2004, 6, 2885. For the development of new Mitsunobu reagents, see: (l) Tsunoda T, Ito, S. J. Synth. Org. Chem. Jpn. 1997, 50, 631.
2. Reviews: (a) Mitsunobu, O. Synthesis 1981, 1. (b) Hughes, D. L. Org. Prep. Proced. Int. 1996, 28, 127. Mechanistic studies (c) Hughes, D. L. Org. React. 1992, 42, 335. (d) Camp, D.; Jenkins, I. D. J. Org. Chem. 1989, 54, 3045. (e) Camp, D.; Jenkins, I. D. J. Org. Chem. 1989, 54, 3049. (f) Wilson, S. R.; Perez, J.; Pasternak, A. J. Am. Chem. Soc. 1993, 115, 1994. (g) Hughes, D. L.; Reamer, R. A. J. Org. Chem. 1996, 61, 2967. (h) Watanabe, T.; Gridnev, I. D.; Imamoto, T. Chirality 2000, 12, 346. (i) Ahn, C.; Correia, R.; DeShong, P. J. Org. Chem. 2002, 67, 1751. (j) McNulty, J.; Capretta, A.; Laritchev, V.; Dyck, J.; Robertson, A. J. Angew. Chem., Int. Ed. 2003, 42, 4051. (k) Dinsmore C. J.; Mercer, S. P. Org. Lett. 2004, 6, 2885. For the development of new Mitsunobu reagents, see: (l) Tsunoda T, Ito, S. J. Synth. Org. Chem. Jpn. 1997, 50, 631.
3. Reviews: (a) Mitsunobu, O. Synthesis 1981, 1. (b) Hughes, D. L. Org. Prep. Proced. Int. 1996, 28, 127. Mechanistic studies (c) Hughes, D. L. Org. React. 1992, 42, 335. (d) Camp, D.; Jenkins, I. D. J. Org. Chem. 1989, 54, 3045. (e) Camp, D.; Jenkins, I. D. J. Org. Chem. 1989, 54, 3049. (f) Wilson, S. R.; Perez, J.; Pasternak, A. J. Am. Chem. Soc. 1993, 115, 1994. (g) Hughes, D. L.; Reamer, R. A. J. Org. Chem. 1996, 61, 2967. (h) Watanabe, T.; Gridnev, I. D.; Imamoto, T. Chirality 2000, 12, 346. (i) Ahn, C.; Correia, R.; DeShong, P. J. Org. Chem. 2002, 67, 1751. (j) McNulty, J.; Capretta, A.; Laritchev, V.; Dyck, J.; Robertson, A. J. Angew. Chem., Int. Ed. 2003, 42, 4051. (k) Dinsmore C. J.; Mercer, S. P. Org. Lett. 2004, 6, 2885. For the development of new Mitsunobu reagents, see: (l) Tsunoda T, Ito, S. J. Synth. Org. Chem. Jpn. 1997, 50, 631.
4. Reviews: (a) Mitsunobu, O. Synthesis 1981, 1. (b) Hughes, D. L. Org. Prep. Proced. Int. 1996, 28, 127. Mechanistic studies (c) Hughes, D. L. Org. React. 1992, 42, 335. (d) Camp, D.; Jenkins, I. D. J. Org. Chem. 1989, 54, 3045. (e) Camp, D.; Jenkins, I. D. J. Org. Chem. 1989, 54, 3049. (f) Wilson, S. R.; Perez, J.; Pasternak, A. J. Am. Chem. Soc. 1993, 115, 1994. (g) Hughes, D. L.; Reamer, R. A. J. Org. Chem. 1996, 61, 2967. (h) Watanabe, T.; Gridnev, I. D.; Imamoto, T. Chirality 2000, 12, 346. (i) Ahn, C.; Correia, R.; DeShong, P. J. Org. Chem. 2002, 67, 1751. (j) McNulty, J.; Capretta, A.; Laritchev, V.; Dyck, J.; Robertson, A. J. Angew. Chem., Int. Ed. 2003, 42, 4051. (k) Dinsmore C. J.; Mercer, S. P. Org. Lett. 2004, 6, 2885. For the development of new Mitsunobu reagents, see: (l) Tsunoda T, Ito, S. J. Synth. Org. Chem. Jpn. 1997, 50, 631.
5. Reviews: (a) Mitsunobu, O. Synthesis 1981, 1. (b) Hughes, D. L. Org. Prep. Proced. Int. 1996, 28, 127. Mechanistic studies (c) Hughes, D. L. Org. React. 1992, 42, 335. (d) Camp, D.; Jenkins, I. D. J. Org. Chem. 1989, 54, 3045. (e) Camp, D.; Jenkins, I. D. J. Org. Chem. 1989, 54, 3049. (f) Wilson, S. R.; Perez, J.; Pasternak, A. J. Am. Chem. Soc. 1993, 115, 1994. (g) Hughes, D. L.; Reamer, R. A. J. Org. Chem. 1996, 61, 2967. (h) Watanabe, T.; Gridnev, I. D.; Imamoto, T. Chirality 2000, 12, 346. (i) Ahn, C.; Correia, R.; DeShong, P. J. Org. Chem. 2002, 67, 1751. (j) McNulty, J.; Capretta, A.; Laritchev, V.; Dyck, J.; Robertson, A. J. Angew. Chem., Int. Ed. 2003, 42, 4051. (k) Dinsmore C. J.; Mercer, S. P. Org. Lett. 2004, 6, 2885. For the development of new Mitsunobu reagents, see: (l) Tsunoda T, Ito, S. J. Synth. Org. Chem. Jpn. 1997, 50, 631.
6. Reviews: (a) Mitsunobu, O. Synthesis 1981, 1. (b) Hughes, D. L. Org. Prep. Proced. Int. 1996, 28, 127. Mechanistic studies (c) Hughes, D. L. Org. React. 1992, 42, 335. (d) Camp, D.; Jenkins, I. D. J. Org. Chem. 1989, 54, 3045. (e) Camp, D.; Jenkins, I. D. J. Org. Chem. 1989, 54, 3049. (f) Wilson, S. R.; Perez, J.; Pasternak, A. J. Am. Chem. Soc. 1993, 115, 1994. (g) Hughes, D. L.; Reamer, R. A. J. Org. Chem. 1996, 61, 2967. (h) Watanabe, T.; Gridnev, I. D.; Imamoto, T. Chirality 2000, 12, 346. (i) Ahn, C.; Correia, R.; DeShong, P. J. Org. Chem. 2002, 67, 1751. (j) McNulty, J.; Capretta, A.; Laritchev, V.; Dyck, J.; Robertson, A. J. Angew. Chem., Int. Ed. 2003, 42, 4051. (k) Dinsmore C. J.; Mercer, S. P. Org. Lett. 2004, 6, 2885. For the development of new Mitsunobu reagents, see: (l) Tsunoda T, Ito, S. J. Synth. Org. Chem. Jpn. 1997, 50, 631.
7. Reviews: (a) Mitsunobu, O. Synthesis 1981, 1. (b) Hughes, D. L. Org. Prep. Proced. Int. 1996, 28, 127. Mechanistic studies (c) Hughes, D. L. Org. React. 1992, 42, 335. (d) Camp, D.; Jenkins, I. D. J. Org. Chem. 1989, 54, 3045. (e) Camp, D.; Jenkins, I. D. J. Org. Chem. 1989, 54, 3049. (f) Wilson, S. R.; Perez, J.; Pasternak, A. J. Am. Chem. Soc. 1993, 115, 1994. (g) Hughes, D. L.; Reamer, R. A. J. Org. Chem. 1996, 61, 2967. (h) Watanabe, T.; Gridnev, I. D.; Imamoto, T. Chirality 2000, 12, 346. (i) Ahn, C.; Correia, R.; DeShong, P. J. Org. Chem. 2002, 67, 1751. (j) McNulty, J.; Capretta, A.; Laritchev, V.; Dyck, J.; Robertson, A. J. Angew. Chem., Int. Ed. 2003, 42, 4051. (k) Dinsmore C. J.; Mercer, S. P. Org. Lett. 2004, 6, 2885. For the development of new Mitsunobu reagents, see: (l) Tsunoda T, Ito, S. J. Synth. Org. Chem. Jpn. 1997, 50, 631.
8. Reviews: (a) Mitsunobu, O. Synthesis 1981, 1. (b) Hughes, D. L. Org. Prep. Proced. Int. 1996, 28, 127. Mechanistic studies (c) Hughes, D. L. Org. React. 1992, 42, 335. (d) Camp, D.; Jenkins, I. D. J. Org. Chem. 1989, 54, 3045. (e) Camp, D.; Jenkins, I. D. J. Org. Chem. 1989, 54, 3049. (f) Wilson, S. R.; Perez, J.; Pasternak, A. J. Am. Chem. Soc. 1993, 115, 1994. (g) Hughes, D. L.; Reamer, R. A. J. Org. Chem. 1996, 61, 2967. (h) Watanabe, T.; Gridnev, I. D.; Imamoto, T. Chirality 2000, 12, 346. (i) Ahn, C.; Correia, R.; DeShong, P. J. Org. Chem. 2002, 67, 1751. (j) McNulty, J.; Capretta, A.; Laritchev, V.; Dyck, J.; Robertson, A. J. Angew. Chem., Int. Ed. 2003, 42, 4051. (k) Dinsmore C. J.; Mercer, S. P. Org. Lett. 2004, 6, 2885. For the development of new Mitsunobu reagents, see: (l) Tsunoda T, Ito, S. J. Synth. Org. Chem. Jpn. 1997, 50, 631.
9. Reviews: (a) Mitsunobu, O. Synthesis 1981, 1. (b) Hughes, D. L. Org. Prep. Proced. Int. 1996, 28, 127. Mechanistic studies (c) Hughes, D. L. Org. React. 1992, 42, 335. (d) Camp, D.; Jenkins, I. D. J. Org. Chem. 1989, 54, 3045. (e) Camp, D.; Jenkins, I. D. J. Org. Chem. 1989, 54, 3049. (f) Wilson, S. R.; Perez, J.; Pasternak, A. J. Am. Chem. Soc. 1993, 115, 1994. (g) Hughes, D. L.; Reamer, R. A. J. Org. Chem. 1996, 61, 2967. (h) Watanabe, T.; Gridnev, I. D.; Imamoto, T. Chirality 2000, 12, 346. (i) Ahn, C.; Correia, R.; DeShong, P. J. Org. Chem. 2002, 67, 1751. (j) McNulty, J.; Capretta, A.; Laritchev, V.; Dyck, J.; Robertson, A. J. Angew. Chem., Int. Ed. 2003, 42, 4051. (k) Dinsmore C. J.; Mercer, S. P. Org. Lett. 2004, 6, 2885. For the development of new Mitsunobu reagents, see: (l) Tsunoda T, Ito, S. J. Synth. Org. Chem. Jpn. 1997, 50, 631.
10. Reviews: (a) Mitsunobu, O. Synthesis 1981, 1. (b) Hughes, D. L. Org. Prep. Proced. Int. 1996, 28, 127. Mechanistic studies (c) Hughes, D. L. Org. React. 1992, 42, 335. (d) Camp, D.; Jenkins, I. D. J. Org. Chem. 1989, 54, 3045. (e) Camp, D.; Jenkins, I. D. J. Org. Chem. 1989, 54, 3049. (f) Wilson, S. R.; Perez, J.; Pasternak, A. J. Am. Chem. Soc. 1993, 115, 1994. (g) Hughes, D. L.; Reamer, R. A. J. Org. Chem. 1996, 61, 2967. (h) Watanabe, T.; Gridnev, I. D.; Imamoto, T. Chirality 2000, 12, 346. (i) Ahn, C.; Correia, R.; DeShong, P. J. Org. Chem. 2002, 67, 1751. (j) McNulty, J.; Capretta, A.; Laritchev, V.; Dyck, J.; Robertson, A. J. Angew. Chem., Int. Ed. 2003, 42, 4051. (k) Dinsmore C. J.; Mercer, S. P. Org. Lett. 2004, 6, 2885. For the development of new Mitsunobu reagents, see: (l) Tsunoda T, Ito, S. J. Synth. Org. Chem. Jpn. 1997, 50, 631.
11. Reviews: (a) Mitsunobu, O. Synthesis 1981, 1. (b) Hughes, D. L. Org. Prep. Proced. Int. 1996, 28, 127. Mechanistic studies (c) Hughes, D. L. Org. React. 1992, 42, 335. (d) Camp, D.; Jenkins, I. D. J. Org. Chem. 1989, 54, 3045. (e) Camp, D.; Jenkins, I. D. J. Org. Chem. 1989, 54, 3049. (f) Wilson, S. R.; Perez, J.; Pasternak, A. J. Am. Chem. Soc. 1993, 115, 1994. (g) Hughes, D. L.; Reamer, R. A. J. Org. Chem. 1996, 61, 2967. (h) Watanabe, T.; Gridnev, I. D.; Imamoto, T. Chirality 2000, 12, 346. (i) Ahn, C.; Correia, R.; DeShong, P. J. Org. Chem. 2002, 67, 1751. (j) McNulty, J.; Capretta, A.; Laritchev, V.; Dyck, J.; Robertson, A. J. Angew. Chem., Int. Ed. 2003, 42, 4051. (k) Dinsmore C. J.; Mercer, S. P. Org. Lett. 2004, 6, 2885. For the development of new Mitsunobu reagents, see: (l) Tsunoda T, Ito, S. J. Synth. Org. Chem. Jpn. 1997, 50, 631.
12. Reviews: (a) Mitsunobu, O. Synthesis 1981, 1. (b) Hughes, D. L. Org. Prep. Proced. Int. 1996, 28, 127. Mechanistic studies (c) Hughes, D. L. Org. React. 1992, 42, 335. (d) Camp, D.; Jenkins, I. D. J. Org. Chem. 1989, 54, 3045. (e) Camp, D.; Jenkins, I. D. J. Org. Chem. 1989, 54, 3049. (f) Wilson, S. R.; Perez, J.; Pasternak, A. J. Am. Chem. Soc. 1993, 115, 1994. (g) Hughes, D. L.; Reamer, R. A. J. Org. Chem. 1996, 61, 2967. (h) Watanabe, T.; Gridnev, I. D.; Imamoto, T. Chirality 2000, 12, 346. (i) Ahn, C.; Correia, R.; DeShong, P. J. Org. Chem. 2002, 67, 1751. (j) McNulty, J.; Capretta, A.; Laritchev, V.; Dyck, J.; Robertson, A. J. Angew. Chem., Int. Ed. 2003, 42, 4051. (k) Dinsmore C. J.; Mercer, S. P. Org. Lett. 2004, 6, 2885. For the development of new Mitsunobu reagents, see: (l) Tsunoda T, Ito, S. J. Synth. Org. Chem. Jpn. 1997, 50, 631.
13. (a) Kolasa, T.; Miller, M. J. J. Org. Chem. 1987, 52, 4978.
14. (b) Kurihara, T.; Sugizaki, M.; Kime, I.; Wada, M.; Mitsunobu, O. Bull. Chem. Soc. Jpn. 1981, 54, 2107.
15. Satish Kumar, N.; Praveen Kumar, K.; Pavan Kumar, K. V. P.; Kommana, P.; Vittal, J. J.; Kumara Swamy, K. C. J. Org. Chem. 2004, 69, 1880.
16. (a) Liu, Y.; Xu, C.; Liu, L. Synthesis 2003, 1335.
17. For other vinylhydrazine dicarboxylates synthesis, see: (b) Kabalka, G. W.; Guchhait, S. K. Org. Lett. 2003, 5, 4129. (c) Lee, C. B.; Newman, R. J. J.; Taylor, D. R. J. Chem. Soc., Perkin Trans. 1 1976, 1161. (d) Bloch, J. C. Tetrahedron 1969, 25, 619.
18. For other vinylhydrazine dicarboxylates synthesis, see: (b) Kabalka, G. W.; Guchhait, S. K. Org. Lett. 2003, 5, 4129. (c) Lee, C. B.; Newman, R. J. J.; Taylor, D. R. J. Chem. Soc., Perkin Trans. 1 1976, 1161. (d) Bloch, J. C. Tetrahedron 1969, 25, 619.
19. For other vinylhydrazine dicarboxylates synthesis, see: (b) Kabalka, G. W.; Guchhait, S. K. Org. Lett. 2003, 5, 4129. (c) Lee, C. B.; Newman, R. J. J.; Taylor, D. R. J. Chem. Soc., Perkin Trans. 1 1976, 1161. (d) Bloch, J. C. Tetrahedron 1969, 25, 619.
20. This type of cyclic structure was also generated from a different route; see: Mukaiyama, T.; Atsumi, K.; Takeda, T. Chem. Lett. 1976, 597.
21. Although an intramolecular proton abstraction is indicated, that does not exclude the intermolecular process.
22. The spectroscopic data of 10b are identical to those of 13b in ref 2a, one of compounds assigned as 4 possessing methyl instead of benzyl group.
23. The same type of compounds was synthesized from ethyl vinyl ketone and azodicarboxylate via Morita-Baylis-Hillman reaction; see: Kamimura, A.; Gunjigake, Y.; Mitsudera, H.; Yokoyama, S. Tetrahedron. Lett. 1998, 39, 7323.
24. Compound 13i shows strong NOE between the methyl and a vinyl proton, indicating the stereochemistry shown in the structure.
25. For other methods for the preparation of 1,3-dienes, see: (a) Barluenga, J.; Aznar, F.; Valdes, C.; Martin, F.; Garcia-Granda, S.; Martin, E. J. Am. Chem. Soc. 1993, 15, 4403. (b) Enders, D.; Meyer, O.; Raabe, G. Synthesis 1992, 1242. (c) Benedetti, F.; Pitacco, G.; Valentin, E. Tetrahedron 1979, 35, 2293. (d) Barluenga, J.; Aznar, F.; Liz, R.; Cabal, M. J. Chem. Soc., Chem. Commun. 1985, 20, 1375. (e) Barluenga, J.; Merino, I.; Palacios, F. Tetrahedron Lett. 1990, 31, 6713. (f) Veronese, A. C.; Morelli, C. F.; Basato, M. Tetrahedron 2002, 58, 9709. (g) Maas, G.; Mayer, T. Synthesis 1991, 1209. (h) Mass, G.; Brunner, M. Synthesis 1995, 957. (i) Enders, D.; Hecker, P.; Meyer, O. Tetrahedron 1996, 52, 2909. (j) David, O.; Vanucci-Bacque, C. Heterocycles 2004, 62, 839.
26. For other methods for the preparation of 1,3-dienes, see: (a) Barluenga, J.; Aznar, F.; Valdes, C.; Martin, F.; Garcia-Granda, S.; Martin, E. J. Am. Chem. Soc. 1993, 15, 4403. (b) Enders, D.; Meyer, O.; Raabe, G. Synthesis 1992, 1242. (c) Benedetti, F.; Pitacco, G.; Valentin, E. Tetrahedron 1979, 35, 2293. (d) Barluenga, J.; Aznar, F.; Liz, R.; Cabal, M. J. Chem. Soc., Chem. Commun. 1985, 20, 1375. (e) Barluenga, J.; Merino, I.; Palacios, F. Tetrahedron Lett. 1990, 31, 6713. (f) Veronese, A. C.; Morelli, C. F.; Basato, M. Tetrahedron 2002, 58, 9709. (g) Maas, G.; Mayer, T. Synthesis 1991, 1209. (h) Mass, G.; Brunner, M. Synthesis 1995, 957. (i) Enders, D.; Hecker, P.; Meyer, O. Tetrahedron 1996, 52, 2909. (j) David, O.; Vanucci-Bacque, C. Heterocycles 2004, 62, 839.
27. For other methods for the preparation of 1,3-dienes, see: (a) Barluenga, J.; Aznar, F.; Valdes, C.; Martin, F.; Garcia-Granda, S.; Martin, E. J. Am. Chem. Soc. 1993, 15, 4403. (b) Enders, D.; Meyer, O.; Raabe, G. Synthesis 1992, 1242. (c) Benedetti, F.; Pitacco, G.; Valentin, E. Tetrahedron 1979, 35, 2293. (d) Barluenga, J.; Aznar, F.; Liz, R.; Cabal, M. J. Chem. Soc., Chem. Commun. 1985, 20, 1375. (e) Barluenga, J.; Merino, I.; Palacios, F. Tetrahedron Lett. 1990, 31, 6713. (f) Veronese, A. C.; Morelli, C. F.; Basato, M. Tetrahedron 2002, 58, 9709. (g) Maas, G.; Mayer, T. Synthesis 1991, 1209. (h) Mass, G.; Brunner, M. Synthesis 1995, 957. (i) Enders, D.; Hecker, P.; Meyer, O. Tetrahedron 1996, 52, 2909. (j) David, O.; Vanucci-Bacque, C. Heterocycles 2004, 62, 839.
28. For other methods for the preparation of 1,3-dienes, see: (a) Barluenga, J.; Aznar, F.; Valdes, C.; Martin, F.; Garcia-Granda, S.; Martin, E. J. Am. Chem. Soc. 1993, 15, 4403. (b) Enders, D.; Meyer, O.; Raabe, G. Synthesis 1992, 1242. (c) Benedetti, F.; Pitacco, G.; Valentin, E. Tetrahedron 1979, 35, 2293. (d) Barluenga, J.; Aznar, F.; Liz, R.; Cabal, M. J. Chem. Soc., Chem. Commun. 1985, 20, 1375. (e) Barluenga, J.; Merino, I.; Palacios, F. Tetrahedron Lett. 1990, 31, 6713. (f) Veronese, A. C.; Morelli, C. F.; Basato, M. Tetrahedron 2002, 58, 9709. (g) Maas, G.; Mayer, T. Synthesis 1991, 1209. (h) Mass, G.; Brunner, M. Synthesis 1995, 957. (i) Enders, D.; Hecker, P.; Meyer, O. Tetrahedron 1996, 52, 2909. (j) David, O.; Vanucci-Bacque, C. Heterocycles 2004, 62, 839.
29. For other methods for the preparation of 1,3-dienes, see: (a) Barluenga, J.; Aznar, F.; Valdes, C.; Martin, F.; Garcia-Granda, S.; Martin, E. J. Am. Chem. Soc. 1993, 15, 4403. (b) Enders, D.; Meyer, O.; Raabe, G. Synthesis 1992, 1242. (c) Benedetti, F.; Pitacco, G.; Valentin, E. Tetrahedron 1979, 35, 2293. (d) Barluenga, J.; Aznar, F.; Liz, R.; Cabal, M. J. Chem. Soc., Chem. Commun. 1985, 20, 1375. (e) Barluenga, J.; Merino, I.; Palacios, F. Tetrahedron Lett. 1990, 31, 6713. (f) Veronese, A. C.; Morelli, C. F.; Basato, M. Tetrahedron 2002, 58, 9709. (g) Maas, G.; Mayer, T. Synthesis 1991, 1209. (h) Mass, G.; Brunner, M. Synthesis 1995, 957. (i) Enders, D.; Hecker, P.; Meyer, O. Tetrahedron 1996, 52, 2909. (j) David, O.; Vanucci-Bacque, C. Heterocycles 2004, 62, 839.
30. For other methods for the preparation of 1,3-dienes, see: (a) Barluenga, J.; Aznar, F.; Valdes, C.; Martin, F.; Garcia-Granda, S.; Martin, E. J. Am. Chem. Soc. 1993, 15, 4403. (b) Enders, D.; Meyer, O.; Raabe, G. Synthesis 1992, 1242. (c) Benedetti, F.; Pitacco, G.; Valentin, E. Tetrahedron 1979, 35, 2293. (d) Barluenga, J.; Aznar, F.; Liz, R.; Cabal, M. J. Chem. Soc., Chem. Commun. 1985, 20, 1375. (e) Barluenga, J.; Merino, I.; Palacios, F. Tetrahedron Lett. 1990, 31, 6713. (f) Veronese, A. C.; Morelli, C. F.; Basato, M. Tetrahedron 2002, 58, 9709. (g) Maas, G.; Mayer, T. Synthesis 1991, 1209. (h) Mass, G.; Brunner, M. Synthesis 1995, 957. (i) Enders, D.; Hecker, P.; Meyer, O. Tetrahedron 1996, 52, 2909. (j) David, O.; Vanucci-Bacque, C. Heterocycles 2004, 62, 839.
31. For other methods for the preparation of 1,3-dienes, see: (a) Barluenga, J.; Aznar, F.; Valdes, C.; Martin, F.; Garcia-Granda, S.; Martin, E. J. Am. Chem. Soc. 1993, 15, 4403. (b) Enders, D.; Meyer, O.; Raabe, G. Synthesis 1992, 1242. (c) Benedetti, F.; Pitacco, G.; Valentin, E. Tetrahedron 1979, 35, 2293. (d) Barluenga, J.; Aznar, F.; Liz, R.; Cabal, M. J. Chem. Soc., Chem. Commun. 1985, 20, 1375. (e) Barluenga, J.; Merino, I.; Palacios, F. Tetrahedron Lett. 1990, 31, 6713. (f) Veronese, A. C.; Morelli, C. F.; Basato, M. Tetrahedron 2002, 58, 9709. (g) Maas, G.; Mayer, T. Synthesis 1991, 1209. (h) Mass, G.; Brunner, M. Synthesis 1995, 957. (i) Enders, D.; Hecker, P.; Meyer, O. Tetrahedron 1996, 52, 2909. (j) David, O.; Vanucci-Bacque, C. Heterocycles 2004, 62, 839.
32. For other methods for the preparation of 1,3-dienes, see: (a) Barluenga, J.; Aznar, F.; Valdes, C.; Martin, F.; Garcia-Granda, S.; Martin, E. J. Am. Chem. Soc. 1993, 15, 4403. (b) Enders, D.; Meyer, O.; Raabe, G. Synthesis 1992, 1242. (c) Benedetti, F.; Pitacco, G.; Valentin, E. Tetrahedron 1979, 35, 2293. (d) Barluenga, J.; Aznar, F.; Liz, R.; Cabal, M. J. Chem. Soc., Chem. Commun. 1985, 20, 1375. (e) Barluenga, J.; Merino, I.; Palacios, F. Tetrahedron Lett. 1990, 31, 6713. (f) Veronese, A. C.; Morelli, C. F.; Basato, M. Tetrahedron 2002, 58, 9709. (g) Maas, G.; Mayer, T. Synthesis 1991, 1209. (h) Mass, G.; Brunner, M. Synthesis 1995, 957. (i) Enders, D.; Hecker, P.; Meyer, O. Tetrahedron 1996, 52, 2909. (j) David, O.; Vanucci-Bacque, C. Heterocycles 2004, 62, 839.
33. For other methods for the preparation of 1,3-dienes, see: (a) Barluenga, J.; Aznar, F.; Valdes, C.; Martin, F.; Garcia-Granda, S.; Martin, E. J. Am. Chem. Soc. 1993, 15, 4403. (b) Enders, D.; Meyer, O.; Raabe, G. Synthesis 1992, 1242. (c) Benedetti, F.; Pitacco, G.; Valentin, E. Tetrahedron 1979, 35, 2293. (d) Barluenga, J.; Aznar, F.; Liz, R.; Cabal, M. J. Chem. Soc., Chem. Commun. 1985, 20, 1375. (e) Barluenga, J.; Merino, I.; Palacios, F. Tetrahedron Lett. 1990, 31, 6713. (f) Veronese, A. C.; Morelli, C. F.; Basato, M. Tetrahedron 2002, 58, 9709. (g) Maas, G.; Mayer, T. Synthesis 1991, 1209. (h) Mass, G.; Brunner, M. Synthesis 1995, 957. (i) Enders, D.; Hecker, P.; Meyer, O. Tetrahedron 1996, 52, 2909. (j) David, O.; Vanucci-Bacque, C. Heterocycles 2004, 62, 839.
34. For other methods for the preparation of 1,3-dienes, see: (a) Barluenga, J.; Aznar, F.; Valdes, C.; Martin, F.; Garcia-Granda, S.; Martin, E. J. Am. Chem. Soc. 1993, 15, 4403. (b) Enders, D.; Meyer, O.; Raabe, G. Synthesis 1992, 1242. (c) Benedetti, F.; Pitacco, G.; Valentin, E. Tetrahedron 1979, 35, 2293. (d) Barluenga, J.; Aznar, F.; Liz, R.; Cabal, M. J. Chem. Soc., Chem. Commun. 1985, 20, 1375. (e) Barluenga, J.; Merino, I.; Palacios, F. Tetrahedron Lett. 1990, 31, 6713. (f) Veronese, A. C.; Morelli, C. F.; Basato, M. Tetrahedron 2002, 58, 9709. (g) Maas, G.; Mayer, T. Synthesis 1991, 1209. (h) Mass, G.; Brunner, M. Synthesis 1995, 957. (i) Enders, D.; Hecker, P.; Meyer, O. Tetrahedron 1996, 52, 2909. (j) David, O.; Vanucci-Bacque, C. Heterocycles 2004, 62, 839.
35. We appreciate the comment from one of the reviewers, suggesting alternative mechanistic rationale for the formation of different products (10, 11, 13, 15) from the common intermediate 8′ due to the stability and reactivity difference caused by the substituent R and R′.