Enantioselective synthesis of cuparane sesquiterpenes. Synthesis of (-)-cuparene and (-)-δ-cuparenol

Journal of Organic Chemistry

Volumn 61, Issue 17, 1996, Pages 5916-5919

  Abad, Antonio ^a   Agulló, Consuelo ^a   Arnó, Manuel ^a   Cuñat, Ana C ^a   García, M Teresa ^a   Zaragozá, Ramón J ^a  

^a UNIVERSITY OF VALENCIA   (Spain)

Author keywords

[No Author keywords available]

Indexed keywords

CUPARENE; CUPARENOL; SESQUITERPENE; UNCLASSIFIED DRUG;

ARTICLE; DRUG SYNTHESIS; ENANTIOMER; REACTION ANALYSIS;

EID: 0029842034     PISSN: 00223263     EISSN: None     Source Type: Journal    
DOI: 10.1021/jo960463g     Document Type: Article

References (21)

1. Connolly, J. D.; Hill, R. A. In Dictionary of Terpenoids, 1st ed.; Chapman and Hall: London, 1991; Vol. 1; pp 295-298. Also see: Fraga, B. M. Nat. Prod. Rep. 1992, 9, 217; 1993, 10, 397; 1994, 11, 536; 1995, 12, 306.
2. Connolly, J. D.; Hill, R. A. In Dictionary of Terpenoids, 1st ed.; Chapman and Hall: London, 1991; Vol. 1; pp 295-298. Also see: Fraga, B. M. Nat. Prod. Rep. 1992, 9, 217; 1993, 10, 397; 1994, 11, 536; 1995, 12, 306.
3. Connolly, J. D.; Hill, R. A. In Dictionary of Terpenoids, 1st ed.; Chapman and Hall: London, 1991; Vol. 1; pp 295-298. Also see: Fraga, B. M. Nat. Prod. Rep. 1992, 9, 217; 1993, 10, 397; 1994, 11, 536; 1995, 12, 306.
4. Connolly, J. D.; Hill, R. A. In Dictionary of Terpenoids, 1st ed.; Chapman and Hall: London, 1991; Vol. 1; pp 295-298. Also see: Fraga, B. M. Nat. Prod. Rep. 1992, 9, 217; 1993, 10, 397; 1994, 11, 536; 1995, 12, 306.
5. Connolly, J. D.; Hill, R. A. In Dictionary of Terpenoids, 1st ed.; Chapman and Hall: London, 1991; Vol. 1; pp 295-298. Also see: Fraga, B. M. Nat. Prod. Rep. 1992, 9, 217; 1993, 10, 397; 1994, 11, 536; 1995, 12, 306.
6. For previous synthesis of cuparane-type sesquiterpenoids, see: (a) Schuda, P. F.; Potlock, S. J.; Ziffer, H. Tetrahedron 1987, 43, 463 and references cited therein. (b) Nakatani, H.; So, T. S.; Ishibashi, H.; Ikeda, M. Chem. Pharm. Bull. 1990, 38, 1233 and references cited therein. (c) Schwarz, J. B.; Meyers, A. I. J. Org. Chem. 1995, 60, 6511.
7. For previous synthesis of cuparane-type sesquiterpenoids, see: (a) Schuda, P. F.; Potlock, S. J.; Ziffer, H. Tetrahedron 1987, 43, 463 and references cited therein. (b) Nakatani, H.; So, T. S.; Ishibashi, H.; Ikeda, M. Chem. Pharm. Bull. 1990, 38, 1233 and references cited therein. (c) Schwarz, J. B.; Meyers, A. I. J. Org. Chem. 1995, 60, 6511.
8. For previous synthesis of cuparane-type sesquiterpenoids, see: (a) Schuda, P. F.; Potlock, S. J.; Ziffer, H. Tetrahedron 1987, 43, 463 and references cited therein. (b) Nakatani, H.; So, T. S.; Ishibashi, H.; Ikeda, M. Chem. Pharm. Bull. 1990, 38, 1233 and references cited therein. (c) Schwarz, J. B.; Meyers, A. I. J. Org. Chem. 1995, 60, 6511.
9. 4, -78 °C to rt; 56% yield).
10. In the same way, the use of the Sharpless D-(-)-DET reagent afforded enantiomeric (1R,2R)-6, which can be used as chiral template for the construction of cuparane terpenoids belonging to the antipodal series of that described here.
11. A slight loss of optical purity occurs during the rearrangement of 7 to 4. See ref 3.
12. Boeckmam, R. K., Jr.; Blum, D. M.; Ganem, B.; Halvey, N. Organic Syntheses; Wiley: New York, 1988; Collect. Vol. VI, p 1033.
13. The use of methyl vinyl ketone (MVK) in the Michael reaction afforded the expected adduct 10 in very low yield. LDA (1 equiv), MVK (1 equiv), -78 to +25 °C; 5-10% yield. The use of an excess of MVK gave a complex reaction mixture from which compound i was obtained as the only identified compound. This compound, obtained as a mixture of diastereomers, was formed by two consecutive Michael reactions with MVK, followed by aldol ring closure. equation presented
14. Jung, M. E. Tetrahedron 1976, 32, 3.
15. 6, 100 °C, 70%). However, the global yield for the conversion of β-cyclogeraniol (5) into 3 through this route was lower (ca. 22%) than that obtained with the route described in the discussion section (vide infra). (11) Obtained as a chromatographically homogeneous 1:1 mixture of diastereomers with respect to the newly created quiral centre.
16. Lee, J. G.; Kim, K. C. Tetrahedron Lett. 1992, 42, 6363.
17. 2O in pentane at -78 °C. Cyclohexadiene 15, which was obtained accompanied by variable amounts of dienic regioisomers (ca. 20%), is also a naturally occurring cuparane sesquiterpene. See: Dauben, W. G.; Oberhänsly, P. J. Org. Chem. 1966, 31, 315.
18. Matsuo, A.; Nakayama, N.; Nakayama, M. Phytochemistry 1985, 24, 777.
19. Asakawa, Y.; Takeda, R.; Toyota, M.; Takemoto, T. Phytochemistry 1981, 20, 858.
20. Connolly, J. D.; Hill, R. A. In Dictionary of Terpenoids, 1st ed.; Chapman and Hall: London, 1991; Vol. 1, pp 299-300.
21. Abad, A.; Agulló, C.; Arnó, M.; Cuñat, A. C.; Zaragozá, R. J. J. Org. Chem. 1992, 57, 50.