Abstract
EPR spectroscopy of 3-hydroxyesculetin (1, solid and in solution) and of the radicals formed during the aerobic oxidation of alkaline solutions of 1 and related compounds was investigated. 1 in the solid state was studied by pulsed EPR experiments and showed a radical character. The aerobic oxidation of alkaline solutions of 1 was also followed by EPR spectroscopy. A ring contraction occurred leading to a 5,6-dihydroxybenzofuran-2-carboxylate radical. The autoxidation of an alkaline solution of (Z)-3-(3,4-dihydroxyphenyl)-2-hydroxypropenoic acid allowed the observation of a spectrum attributable to 5,6-dihydroxybenzofuran-3-one-2-carboxylate radical. The formation mechanisms of these radicals are discussed.
This is a preview of subscription content, log in via an institution to check access.
Similar content being viewed by others
REFERENCES
Y. Lu, L. Y. Foo and H. Wong, Phytochemistry 52, 1149 (1999).
Y. Lu and L. Y. Foo, Food Chem. 75, 197 (2001).
F. A. Macias, A. M. Simonet, J. C. G. Galindo and D. Castellano, Phytochemistry 50, 35 (1999).
R. Dupont and P. Cotelle, Tetrahedron Lett. 42, 597 (2001).
P. J. O'Malley, J. Am. Chem. Soc. 120, 5093 (1998).
P. J. O'Malley, J. Phys. Chem. B 105, 11290 (2001).
H. N. C. Wong, Z. L. Xu, H. M. Chang and C. M. Lee, Synthesis, 793 (1992).
E. Boschetti, D. Molho and L. Fontaine, South African Patent No. 68 01,304 (Chem. Abstr. 70, 77791m) (1968).
V. Barone, in: D. P. Chong (Eds), Recent Advances in Density Functional Methods. World Scienti. c Publishing, Singapore (1995).
P. Ashworth, J. Org. Chem. 41, 2920 (1976).
C. C. Felix and R. C. Sealy, J. Am. Chem. Soc. 103, 2831 (1981).
S. Capelle, C. Paillat, P. Cotelle, B. Planckaert and J. P. Catteau, Redox Rep. 1, 219 (1995).
J. D. R. Clay and D. Murphy, J. Chem. Soc., Perkin Trans. 2, 1781 (1984).
J. Pilar, I. Buben and J. Pospisil, Collect. Czech. Chem. Commun. 37, 3599 (1972).
A. A. Frimer, V. Marks, P. Gilinsky-Sharon, G. Aljadeff and H. E. Gottlieb, J. Org. Chem. 60, 4510 (1995).
F. Pattus and M. A. Abdallah, J. Chin. Chem. Soc. 47, 1 (2000).
Rights and permissions
About this article
Cite this article
Cotelle, P., Vezin, H. EPR of free radicals formed from 3-hydroxyesculetin and related derivatives. Research on Chemical Intermediates 29, 365–377 (2003). https://doi.org/10.1163/156856703765694318
Issue Date:
DOI: https://doi.org/10.1163/156856703765694318