Bradley University, Department of Chemistry and Biochemistry, peoria, IL 61625
Recently we discovered that the treatment of substituted benzaldehydes and acetoacetate esters with potassium carbonate in absolute ethanol or methanol yields 5-aryl-3-oxo-delta-lactones (6-aryl-dihydro-2H-pyran-2,4(3H)-diones) after workup with dilute HCl(aq). This development is significant because it provides a simple method for preparing the fundamental ring system (3-oxo-delta-lactone) for a class of compounds that have a wide variety of biological activities. For example, 5-aryl-3-oxo-δ-lactones have been shown to have antioxidant activity, and they have been converted into antiviral agents. In addition, Eifler-Lima has reported that 3-oxo-5-phenyl-delta-lactone and 3-oxo-5-(4-fluorophenyl)-delta-lactone have antinociceptive (pain relieving) activity in mice. We have shown that these compounds inhibit cyclooxygenase (COX) enzymes, which may explain why these compounds exhibit antinociceptive activity. Details of our synthetic work as well as results from chemiluminescence cyclooxygenase inhibition assay will be presented.
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