Anomalous high reactivity of formyl and acetone ketyl radicals with uracil and its derivatives

CO2·− and (CH3)2·COH radicals apparently react with uracil and its derivatives, containing two carbonyl groups, with high rate constants (k=1010 dm3 mol−1 s−1). Various mechanistic aspects of such reactions have been probed. The effect of pH and buffer concentration on the initial formation of absorbance points to some keto-enol tautomerism-type fast-reaction between OH− and the substrate, followed by a slower relaxation to the original equilibrium. The radical anions of these compounds react with methyl viologen mainly via an electron transfer reaction with a high rate constant value (4–9)×109 dm3 mol−1 s−1.