α-Oximierung von gesättigten Ketonen durch das photochemisch angeregte Nitrit-Ion

The photochemical behaviour of the nitrite ion must be considered as being similar to that of the carbonyl group. Like the carbonyl group, the nitrite ion in n, π* excitation is capable of abstracting hydrogen atoms from various compounds. During this reaction the nitrite ion is reduced to NO. The radicals obtained by abstracting α-H atoms from saturated ketones then react with the NO to give nitroso derivatives which undergo a rearrangement to the corresponding oximes - provided that the same carbon bears further hydrogen atoms. Dimethylformamide and probably also acetylacetone act as quenchers in this photoreaction, whereas aromatic aldehydes and excess NO do not.