Intramolecular CuCl-mediated oxidative coupling of alkenyltrimethylstannane functions: An effective method for the construction of carbocyclic 1,3-diene systems

Journal of the American Chemical Society

Volumn 118, Issue 5, 1996, Pages 1215-1216

  Piers, Edward ^a   Romero, Miguel A ^a  

^a UNIVERSITY OF BRITISH COLUMBIA   (Canada)

Author keywords

[No Author keywords available]

Indexed keywords

CYCLOALKENE;

ARTICLE; DRUG SYNTHESIS; REACTION ANALYSIS; TECHNIQUE;

EID: 0029935232     PISSN: 00027863     EISSN: None     Source Type: Journal    
DOI: 10.1021/ja953648y     Document Type: Article

References (20)

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2. (b) Mitchell, T. N. Synthesis 1992, 803.
3. Scott, W. J.; Crisp, G. T.; Stille, J. K. Org. Synth. 1990, 68, 116.
4. (a) Piers, E.; Friesen, R. W.; Keay, B. A. Tetrahedron 1991, 47, 4555.
5. (b) Piers, E.; Friesen, R. W. Can. J. Chem. 1992, 70, 1204.
6. (c) Piers, E.; Friesen, R. W.; Rettig, S. J. Can. J. Chem. 1992, 70, 1385.
7. Piers, E.; Wong, T. J. Org. Chem. 1993, 58, 3609.
8. All new compounds reported herein exhibit spectra in accord with assigned structures and gave satisfactory elemental (C. H) analyses and/or molecular mass determinations (high-resolution mass spectrometry).
9. 7
10. Piers, E.; Tse, H. L. A. Can. J. Chem. 1993, 71, 983.
11. Bloch, R. Synthesis 1978, 140.
12. The yield of this process, as well as that of each of the other alkylations described herein, has not yet been optimized.
13. Presumably, the enolate of 1 reacts with 13 to afford (primarily) the 3-bromo derivative of 1, which then alkylates the γ-position of the enolate to produce 4. This interesting transformation is currently being studied in more detail. The relative configuration of 4 was determined by an X-ray crystallographic study on the corresponding cyclization product 18 (vide infra).
14. 2 in the presence of imidazole, provided the required allylic bromides 14 (86%) and 15 (92%), respectively.
15. Solutions (THF) of each of the alkylating agents employed in this work were passed through a plug of dry basic alumina immediately prior to use.
16. 3c
17. Details of this X-ray crystallographic study will be presented elsewhere. We are very grateful to Dr. Steven J. Rettig for carrying out this structure determination.
18. The effect of using varying amounts of CuCl on conversion of starting material into product, and the quantification of the amount of copper metal produced during the cyclization process, were determined by studying the transformation of 6 into 20. Details of these investigations will be given in a full account of this work.
19. Farina, V.; Kapadia, S.; Krishnan, B.; Wang, C.; Liebeskind, L. S. J. Org. Chem. 1994, 59, 5905.
20. Piers, E.; McEachern, E. J.; Burns, P. A. J. Org. Chem. 1995, 60, 2322.