The oxygenation of the potassium salts of alkylnitronates in absolute DMSO leads to potassium nitrite (nitrate) and the corresponding aldehydes or ketones at 40 degrees C. Kinetic measurements for potassium 1-propylnitronate (K-1-PN) resulted in the rate law -d[K-1-PN]/dt=k(2)[K-1-PN][O-2]. The rate constant, activation enthalpy, and entropy at 313.16 K are as follows: k/M-1 s(-1)=(1.43 +/-004), Delta H-double dagger/kJ mol(-1)=57 +/- 10 Delta S-double dagger/J mol(-1) K-1=-60 +/- 32. The presence of superoxide ion as a result of a SET from the nitronate to dioxygen was proved by NBT test.