A short synthesis of (-)-dendrobine

Journal of the American Chemical Society

Volumn 121, Issue 25, 1999, Pages 6072-6073

  Cassayare, Jérôme ^a   Zard, Samir Z ^a,b  

^a CNRS   (France)

^b LABORATOIRE DE SYNTHÈSE ORGANIQUE   (France)

Author keywords

[No Author keywords available]

Indexed keywords

ALKALOID; DENDROBINE; UNCLASSIFIED DRUG;

ANTIHYPERTENSIVE ACTIVITY; ANTIPYRETIC ACTIVITY; ARTICLE; CYCLIZATION; DRUG SYNTHESIS; ENANTIOMER; PLANT; REACTION ANALYSIS; STEREOCHEMISTRY; STRUCTURE ANALYSIS;

EID: 0033618104     PISSN: 00027863     EISSN: None     Source Type: Journal    
DOI: 10.1021/ja990707p     Document Type: Article

References (45)

1. (a) Suzuki, H.; Keimatsu, I.; Ito, K. J. Pharm. Soc. Jpn. 1932, 52, 1049-1060.
2. (b) Suzuki, H.; Keimatsu, I.; Ito, K. J. Pharm. Soc. Jpn. 1934, 54, 802-812.
3. Porter, L. Chem. Rev. 1967, 67, 441-464.
4. (a) Inubushi, Y.; Sazaki, Y.; Tsuda, Y.; Yasui, B.; Konika, T.; Matsumoto, J. Katarao, E.; Nakano, J. Tetrahedron 1964, 20, 2007-2023.
5. (b) Inubushi, Y.; Sazaki, Y.; Tsuda, Y.; Nakano, J. Tetrahedron Lett. 1965, 20, 1519-1523.
6. (a) Yamada, K.; Suzuki, M.; Hayakawa, Y.; Aoki, K.; Nakamura, H.; Nagase, H.; Hirata, Y. J. Am. Chem. Soc. 1972, 94, 8278-8280.
7. (b) Inubushi, Y.; Kikushi, T.; Ibuka, T.; Tanaka, T.; Saji, I.; Tokane, K. Chem. Pharm. Bull. 1974, 22, 349-369.
8. (c) Kende, A. S.; Bentley, T. J.; Mader, R. A.; Ridge, D. J. Am. Chem. Soc. 1974, 96, 4332-4334.
9. (d) Roush, W. R. J. Am. Chem. Soc. 1980, 102, 1390-1404.
10. (a) Martin, S. F.; Li, W. J. Org. Chem. 1991, 56, 642-650.
11. (b) Trost, B. M.; Tasker, A. S.; Ruther, G.; Brandes, A. J. Am. Chem. Soc. 1991, 113, 670-672.
12. (c) Lee, C. H.; Westling, M.; Livinghouse, T.; Williams, A. C. J. Am. Chem. Soc. 1992, 114, 4089-4095.
13. (d) Mori, M.; Uesaka, N.; Shibasaki, M.; Saitoh, F.; Okamura, K.; Date, T. J. Org. Chem. 1994, 59, 5633-5642.
14. (e) Sha, C.-K.; Chiu, R.-T.; Yang, C.-F.; Yao, N.-T.; Tseng, W.-H.; Liao, F.-L.; Wang, S.-L. J. Am. Chem. Soc. 1997, 119, 4130-4135.
15. For a previous approach to the dendrobine skeleton using the Pauson-Khand reaction, see: Takano, S.; Inomata, K.; Ogasawara, K. Chem. Lett. 1992, 443-446.
16. For recent reviews of the Pauson-Khand reaction, see: (a) Schore, N. E. Org. React. 1991, 40, 1-90.
17. (b) Schore, N. E. In Comprehensive Organic Synthesis; Trost, B. M., Fleming, I., Eds; Pergamon: Oxford, 1991; Vol. 5, pp 1037-1064.
18. (c) Geis, O.; Schmalz, H.-G. Angew. Chem., Int. Ed. 1998, 37, 911-914.
19. For reviews of cyclizations of nitrogen-centered radicals, see: (a) Fallis, A. G.; Brinza, I. M. Tetrahedron 1997, 53, 17543-17594.
20. (b) Zard, S. Z. Synlett 1996, 1148-1158.
21. (a) Callier, A.-C.; Quielet-Sire, B.; Zard, S. Z. Tetrahedron Lett. 1994, 35, 6109-6112.
22. (b) Boivin, J.; Callier-Dublanchet, A.-C.; Quiclet-Sire, B.; Schiano, A.-M.; Zard, S. Z. Tetrahedron 1995, 51, 6517-6528.
23. (c) Callier-Dublanchet, A.-C.; Quiclet-Sire, B.; Zard, S. Z. Tetrahedron Lett. 1995, 36, 8791-8794.
24. We have recently completed a short synthesis of (±)-γ-lycorane involving a cascade process starting with a nitrogen-centered radical: Hoang-Cong, X.; Quiclet-Sire, B.; Zard, S. Z. Tetrahedron Lett. 1999, 39, 2125-2126.
25. Whitham, G. H. J. Chem. Soc. 1961, 2232-2236.
26. This two-step process was best carried out in one pot, without isolation of 4, allowing a simple purification of 3 and separation of tin residues by an acid-base extraction (68% yield from 7).
27. The introduction of a cis vicinal amino alcohol functionality is generally more challenging than for the trans isomer. See: (a) Knapp, S. Chem. Soc. Rev. 1999, 28, 61-72. Interesting compounds in this class include the aminocyclitols (e.g., (+)-valienamine), the aminocyclopentitols (e.g., (+)-mannostatin), or the conduramines:
28. (b) Balci, M.; Sutbeyaz, Y.; Secen, H. Tetrahedron 1993, 49, 8039-8058.
29. (c) Posternak, T. The Cyclitols Holden-Day Inc.: San Francisco, 1965.
30. (d) Trost, B. M.; Van Vranken, D. L. J. Am. Chem. Soc. 1993, 115, 444-458.
31. Our initial plan featured a 5-exo-trig radical cyclization of a dichloroacetamide, induced by the Ni/AcOH combination, recently developed in our laboratory: Cassayre, J.; Quiclet-Sire, B.; Saunier, J.-B.; Zard, S. Z. Tetrahedron 1998, 54, 1029-1040 and references cited therein. In model studies, the cyclization worked well in the absence of the methyl group on C(11); however, when the methyl group was present, a rare 1,4-allylic hydrogen abstraction on C(4) took place. These unwanted, but nevertheless interesting, reactions will be detailed in the full paper.
32. For acceleration of Pauson-Khand cycloadditions with tertiary amine N-oxides, see: (a) Shambayati, S.; Crowe, W. E.; Schreiber, S. L. Tetrahedron Lett. 1990, 31, 5289-5292.
33. (b) Jeong, N.; Chung, Y. K.; Lee, B. Y.; Lee, H. L.; Yoo, S.-E. Synlett 1991, 204-206.
34. Model studies on N-propargyl derivative 17 were undertaken to confirm these intriguing results: under the same conditions, Pauson-Khand reaction of 17 afforded a mixture of expected tricyclic cyclopentenone 18, along with the bicyclic product 19. In the case of 8, a similar ring-opened product was formed, but its structure has not been established unambiguously. The course of the reaction is quite dependent on the solvent, since formation of ring-opened products can be suppressed by using more coordinating solvents, such as acetonitrile. The mechanism for the formation of 19 is still not clear, but (Equation presented) one can speculate that the presence of the basic β-nitrogen within an intermediate complex may induce a β-elimination to give 19 after protonation. Analogous observations have been made with zirconium-mediated [2 + 2 + 1] cycloadditions of related benzylamines: ref 5d and Barluenga, J.; Sanz, R.; Fananas, F. Chem-Eur. J. 1997, 3, 1324-1336. We are not aware of any previous report of such ring-opened products in the Pauson-Khand reaction of propargylic amines, but similar observations were made when allyl propargyl ethers were subjected to Pauson-Khand conditions in the absence of oxygen. In our case, the influence of oxygen was not significant. See ref 15b and Smit, W. A.; Simonyan, S. O.; Tarasov, V. A.; Michaelian, G. S.; Gybin, A. S.; Ibragimov, I. I.; Caple, R.; Froen, D.; Kreager, A. Synthesis 1989, 472-476.
35. Model studies on N-propargyl derivative 17 were undertaken to confirm these intriguing results: under the same conditions, Pauson-Khand reaction of 17 afforded a mixture of expected tricyclic cyclopentenone 18, along with the bicyclic product 19. In the case of 8, a similar ring-opened product was formed, but its structure has not been established unambiguously. The course of the reaction is quite dependent on the solvent, since formation of ring- opened products can be suppressed by using more coordinating solvents, such as acetonitrile. The mechanism for the formation of 19 is still not clear, but (Equation presented) one can speculate that the presence of the basic β-nitrogen within an intermediate complex may induce a β-elimination to give 19 after protonation. Analogous observations have been made with zirconium-mediated [2 + 2 + 1] cycloadditions of related benzylamines: ref 5d and Barluenga, J.; Sanz, R.; Fananas, F. Chem-Eur. J. 1997, 3, 1324-1336. We are not aware of any previous report of such ring-opened products in the Pauson-Khand reaction of propargylic amines, but similar observations were made when allyl propargyl ethers were subjected to Pauson-Khand conditions in the absence of oxygen. In our case, the influence of oxygen was not significant. See ref 15b and Smit, W. A.; Simonyan, S. O.; Tarasov, V. A.; Michaelian, G. S.; Gybin, A. S.; Ibragimov, I. I.; Caple, R.; Froen, D.; Kreager, A. Synthesis 1989, 472-476.
36. For a study of the influence of coordinating solvents on the Pauson-Khand reaction, see: Krafft, M. E.; Scott, I. L.; Romero, R. H.; Feibelmann, S.; Van Pelt, C. E. J. Am. Chem. Soc. 1997, 119, 7199-7207.
37. Miller, R. D.; McKean, D. R. Synthesis 1979, 730-732.
38. 2 afforded a 78:22 mixture of regioisomers in favor of the less substituted isomer. Moreover, model studies have disclosed the importance of the methyl group at C(11) in the regiochemistry of the enol silyl ether formation.
39. For related cyclizations of alcoxycarbonyl radicals, see: (a) Singh, A. K.; Bakshi, R. K.; Corey, E. J. J. Am. Chem. Soc. 1987, 109, 6187-6189.
40. (b) Bachi, M. D.; Bosch, E. J. Org. Chem. 1992, 57, 4696-4705.
41. Surprisingly, upon treatment with phosgene, 11 underwent N-demethylation, and subsequent formation of a tetracyclic oxazolidinone. On the other hand, the carbonyl imidazolide derived from 11 failed to undergo substitution by benzeneselenol, probably because of steric hindrance.
42. It is noteworthy that removal of the acetate group from ketone 9 or cyanoketone 13 induced cyclization of the hydroxy group onto the carbonyl function at C(9) to give the corresponding lactol, which could be isolated as its TMS ether.
43. Barton, D. H. R.; McCombie, S. W. J. Chem. Soc., Perkin Trans. 1 1975, 1574-1585.
44. Compound 16 can be obtained by treatment of 15a with anhydrous p-toluenesulfonic acid in refluxing toluene. For previous isolation of a similar iminolactone, see ref 4b.
45. In principle, it may be possible to convert cyanoketone 13 directly into iminoether 16 (or even to dendrobine) by treatment with hydrazine under Wolff-Kishner conditions. Epimerisation of a similar nitrile under these conditions has already been observed; see ref 4b; unfortunately, preliminary trials have so far proved unsuccessful.