2-Aryl-5-epoxynitrile anion cyclizations : Total syntheses of (±)-α-cuparenone and (±)-epilaurene

Chemistry Letters

Volumn , Issue 5, 2000, Pages 512-513

  Avila Zárraga, J Gustavo ^a   Maldonado, Luis A ^a  

^a Instituto de Quimica de la UNAM   (Mexico)

Author keywords

[No Author keywords available]

Indexed keywords

EID: 0034335801     PISSN: 03667022     EISSN: None     Source Type: Journal    
DOI: 10.1246/cl.2000.512     Document Type: Article

References (17)

1. a) G. Stork, L. D. Cama, and R. D. Coulson, J. Am. Chem.Soc., 96, 5268 (1974).
2. b) G. Stork and J. F. Cohen, J. Am. Chem. Soc., 96, 5270 (1974).
3. For examples of the closely related 6-epoxynitrile anion cyclization see Ref. 1 and R. Achini and W. Oppolzer, Tetrahedron Lett., 1975, 369. Recently, a 7-epoxynitrile anion cyclization has also been reported: A. Nitta, A. Ishiwata, T. Noda, and M. Hirama, Synlett, 1999, 695.
4. For examples of the closely related 6-epoxynitrile anion cyclization see Ref. 1 and R. Achini and W. Oppolzer, Tetrahedron Lett., 1975, 369. Recently, a 7-epoxynitrile anion cyclization has also been reported: A. Nitta, A. Ishiwata, T. Noda, and M. Hirama, Synlett, 1999, 695.
5. For a review on reactions of nitrile carbanions see: S. Arseniyadis, K. S. Kyler, and D. S. Watt, Org. React. (N.Y.), 31, 1 (1984).
6. J. Y. Lallemand and M. Onanga, Tetrahedron Lett., 1975, 585.
7. For previous synthesis of α-cuparenone see: a) M. G. Kulkarni and D. S. Pendharkar, Tetrahedron, 53, 3167 (1997).
8. b) J. Cossy, B. Gille, S. BouzBouz, and V. Bellosta, Tetrahedron Lett., 38, 4069 (1997) and references cited in these papers.
9. For previous synthesis of epilaurene see: A. Fadel, J.-L. Canet, and J. Salaun, Tetrahedron : Asymmetry, 4, 27 (1993) and references cited therein. For a recent synthesis of a 1:1 mixture of epilaurene and laurene see: M. G. Kulkarni and D. S. Pendharkar, J. Chem. Soc., Perkin Trans. I, 1997, 3127.
10. For previous synthesis of epilaurene see: A. Fadel, J.-L. Canet, and J. Salaun, Tetrahedron : Asymmetry, 4, 27 (1993) and references cited therein. For a recent synthesis of a 1:1 mixture of epilaurene and laurene see: M. G. Kulkarni and D. S. Pendharkar, J. Chem. Soc., Perkin Trans. I, 1997, 3127.
11. 2, rt). Some dialkylated product (5-10%) was also isolated in the alkylation reaction.
12. With LDA in THF at rt only traces of epoxide ring opening products were detected after 24 h. Hence, the base and solvent were changed to allow heating.
13. 10 the geometry of the olefin precursor was reasonably assumed to be E.
14. W. Biernacki and A. Gdula, Synthesis, 1979, 37.
15. Cyclopentanone 1a was first prepared by T. Irie, T. Suzuki, Y. Yasunari, E. Kurosawa, and T. Masamune, Tetrahedron, 25, 459 (1969), but in this paper the relative stereochemistry of the 2-methyl and 3-(p-tolyl) groups was incorrectly assigned as syn. See: J. E. McMurry and L. A. von Beroldingen, Tetrahedron, 30, 2027 (1974). See also Ref. 5b for an alternative synthesis of 1a.
16. Cyclopentanone 1a was first prepared by T. Irie, T. Suzuki, Y. Yasunari, E. Kurosawa, and T. Masamune, Tetrahedron, 25, 459 (1969), but in this paper the relative stereochemistry of the 2-methyl and 3-(p-tolyl) groups was incorrectly assigned as syn. See: J. E. McMurry and L. A. von Beroldingen, Tetrahedron, 30, 2027 (1974). See also Ref. 5b for an alternative synthesis of 1a.
17. In the case of cyclobutylcarbinols 4a and 4b the indicated stereochemistry is proposed based on that found, by X-ray analysis, for the derived carboxamide of the phenyl analogue of 4b: G. Avila, L. A. Maldonado, and R. A. Toscano, J. Chem. Cryst., 27, 125 (1997).