Synthesis and photochemistry of spiro[2.5]octa-1,4-dien-3-ones. Reversible biradical formation and biradical-olefin cycloaddition

Tetrahedron Letters

Volumn 37, Issue 33, 1996, Pages 5853-5856

  Schultz, Arthur G ^a   Taveras, Arthur G ^a  

^a Research Rensselaer Polytechnic Institute   (United States)

Author keywords

[No Author keywords available]

Indexed keywords

ALKENE; ETHYLENE DERIVATIVE; NITRILE; PHENOL DERIVATIVE; RADICAL; SPIRO[2.5]OCTA 1,4 DIEN 3 ONE DERIVATIVE; UNCLASSIFIED DRUG;

ALKYLATION; ARTICLE; CHEMICAL MODIFICATION; CYCLIZATION; DECOMPOSITION; DIASTEREOISOMER; ISOMERISM; OXIDATION; PHOTOCHEMISTRY; PHOTOLYSIS; PROTON NUCLEAR MAGNETIC RESONANCE; REDUCTION; SYNTHESIS;

EID: 0030581337     PISSN: 00404039     EISSN: None     Source Type: Journal    
DOI: 10.1016/0040-4039(96)01246-4     Document Type: Article

References (14)

1. 1. (a) Schuster, D. I.; Polowczyk, C. J. J. Am. Chem. Soc. 1964, 86, 4502.
2. (b) Schuster, D. I.; Polowczyk, C. J. J. Am. Chem. Soc. 1966, 88, 1722.
3. (c) Schuster, D. I.; Krull, I. S. J. Am. Chem. Soc. 1966, 88, 3456.
4. (d) Pirkle, W. H.; Smith, S. G.; Koser, G. F. J. Am. Chem. Soc. 1969, 91, 1580.
5. 2. Satisfactory combustion analyses or high resolution mass spectra were obtained for most of the new compounds reported in this paper; low resolution molecular ions were observed for all new compounds.
6. 3. Schultz, A. G.; Taveras, A. G.; Harrington, R. E. Tetrahedron Lett. 1988, 29, 3907.
7. 3) δ (minor diastereomer) 1.80 (m, 1 H), 2.21 (m, 1 H), 2.41 (dd, 1 H, J = 7 Hz, J = 5 Hz), 3.84 (s, 3 H), 5.90 (d, 1 H, J = 1 Hz), 6.02 (d, 1 H, J = 10 Hz), 6.39 (dd, 1 H, J = 10 Hz, J = 1 Hz).
8. 3) δ 2.06 (dd, 1 H, J = 9.7 Hz, J = 4.5 Hz), 2.24 (dd, 1 H, J = 7.4 Hz, J = 4.5 Hz), 2.49 (dd, 1 H, J = 9.7 Hz, J = 7.4 Hz), 3.70 (s, 3 H), 3.80 (s, 3 H), 5.68 (br s, 1 H), 5.75 (br s, 1 H).
9. 6. A by-product from the oxidation of 7b to give 8b (mp 153-154 °C) was the 2,4-cyclohexadien-1-one 18 (mp 102.5-103.5 °C) obtained by flash chromatography on silica gel and crystallization from ethyl acetate and hexane. (equation presented)
10. 1H NMR data. The sharply defined triplet is assigned to the methylene proton anti to the proton at the carbon atom bearing the cyano group. The calculated coupling constant for this relationship is 12 Hz while that for the second methylene proton/methine proton relationship is 5 Hz (MacroModel). Decoupling studies involving irradiation of the methine proton appearing at δ 3.11 caused a collapse of the upfield multiplets to the AB quartet resulting from geminal coupling in the methylene group. (equation presented)
11. 8. For related examples of cyclopentane construction by cycloaddition of diyls to diylophiles, see: Little, R. D. Chem. Rev. 1996, 96, 93.
12. 9. Zimmerman, H. E.; Schuster, D. I. J. Am. Chem. Soc. 1962, 84, 4527.
13. 10. Schultz, A. G.; Lavieri, F. P.; Macielag, M.; Plummer, M. J. Am. Chem. Soc. 1987, 109, 3991.
14. 11. For a discussion of UV spectra of spiro[2.5]octa-1,4-dien-3-ones, see: Baird, R.; Winstein, S. J. Am. Chem. Soc. 1963, 85, 567.