The isomerisation of (Z)-3-[2H1]-phenylprop-2-enone as a measure of the rate of hydroperoxide addition in Weitz-Scheffer and Juliá-Colonna epoxidations

Chemical Communications

Volumn , Issue 18, 2004, Pages 2016-2017

  Kelly, David R ^a   Caroff, Eva ^b   Flood, Robert W ^b   Heal, William ^b   Roberts, Stanley M ^b  

^a CARDIFF UNIVERSITY   (United Kingdom)

^b UNIVERSITY OF LIVERPOOL   (United Kingdom)

Author keywords

[No Author keywords available]

Indexed keywords

3 PHENYLPROP 2 ENONE; ALKENE DERIVATIVE; HYDROPEROXIDE; KETONE DERIVATIVE; LEUCINE; PHENYL GROUP; POLYLEUCINE; UNCLASSIFIED DRUG;

ADDITION REACTION; AQUEOUS SOLUTION; ARTICLE; CHEMICAL REACTION; CHEMICAL STRUCTURE; CYCLIZATION; ELIMINATION REACTION; ENANTIOMER; EPOXIDATION; ISOMER; ISOMERIZATION; OXIDATION; REACTION ANALYSIS; REACTION TIME; STEREOCHEMISTRY; TECHNIQUE;

EID: 6344260329     PISSN: 13597345     EISSN: None     Source Type: Journal    
DOI: 10.1039/b404389h     Document Type: Article

References (18)

1. E. Weitz and A. Scheffer, Ber., 1921, 54, 2327.
2. S. Banfi, S. Colonna, H. Molinari, S. Juliá and J. Guixer, Tetrahedron, 1984, 40, 5207.
3. T. Geller and S. M. Roberts, J. Chem. Soc., Perkin Trans. 1, 1999, 1397 and ref. 3 therein.
4. R. Takagi, A. Shiraki, T. Manabe, S. Kojima and K. Ohkata, Chem. Lett, 2000, 366, ref. 12; R. W. Flood, PhD Thesis, University of Liverpool, 2001.
5. R. Takagi, A. Shiraki, T. Manabe, S. Kojima and K. Ohkata, Chem. Lett, 2000, 366, ref. 12; R. W. Flood, PhD Thesis, University of Liverpool, 2001.
6. C. A. Bunton and G. J. Minkoff, J. Chem. Soc., 1949, 665.
7. R. E. Liutz and W. B. Black, J. Am. Chem. Soc., 1953, 75, 5990; S. Patai, Z. Rappoport, in The Chemistry of the Alkenes, (S. Patai, ed.), Wiley-Interscience, London, 1964, p. 469.
8. R. E. Liutz and W. B. Black, J. Am. Chem. Soc., 1953, 75, 5990; S. Patai, Z. Rappoport, in The Chemistry of the Alkenes, (S. Patai, ed.), Wiley-Interscience, London, 1964, p. 469.
9. H. O. House and R. S. Ro, J. Am. Chem. Soc., 1958, 80, 2428.
10. 2), mp 64-66 °C. An authentic sample was obtained in six steps from styryl alcohol using Sharpless asymmetric epoxidation in the first step.
11. 2O (M. J. Kang, J.-S. Jang and S.-G. Lee, Tetrahedron Lett., 1995, 36, 8829) and Dess-Martin periodinane oxidation (70% overall yield). The ratio (Z)-isomer 1d: (E)-isomer 1e was 95-90: 5-10.
12. Y. Apeloig, M. Kami and Z. Rappoport, J. Am. Chem. Soc., 1983, 105, 2784.
13. V. K. Aggarwal and A. Mereu, Chem. Commun., 1999, 2311.
14. 1H NMR spectroscopy.
15. In a separate experiment it was confirmed that epimerisation of the epoxides 3d, 3e by deprotonation/reprotonation did not occur under the reaction conditions.
16. If every addition occurs with full bond rotation, then the rate of isomerisation is half the rate of addition. Clearly addition-elimination may occur without bond rotation, particularly when the peroxy-enolate 2 is bound to poly-leucine. Therefore the rate of isomerisation is 50% of the lowest possible rate of addition.
17. The absolute configuration is inferred to be (2R,3S) by analogy with the results from Juliá-Colonna oxidation of a wide variety of α,β-unsaturated ketones.
18. The role of the peptide in this mechanism is discussed in the following paper, in this issue (DOI: 10.1039/b404390c).