Autoreduction of 2,2,6,6-tetramethyl-1,4-dioxopiperidinium ion to nitroxyl radical in alkaline medium involves a number of parallel and consecutive reactions. The primary products of the reaction of 2,2,6,6-tetramethyl-1,4-dioxopiperidinium with hydroxide ion are three nitroso compounds and N-hydroxy-2,2,6,6-tetramethylpiperidine N-oxide. Isomerization of the nitroso compounds and elimination of acetone from the N-oxide give cyclic hydroxylamines which reduce the initial cation to nitroxyl radical, being oxidized to nitrones.

中文翻译：

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碱性介质中2,2,6,6-四甲基-1,4-二氧哌啶鎓阳离子的自动还原机理

在碱性介质中将2,2,6,6-四甲基-1,4-二氧代哌啶鎓离子自动还原为硝酰基自由基涉及许多平行和连续的反应。2，2，6，6-四甲基-1，4-二氧哌啶鎓与氢氧根离子反应的主要产物是三种亚硝基化合物和N-羟基-2，2，6，6-四甲基哌啶N-氧化物。亚硝基化合物的异构化和从N-氧化物中除去丙酮得到环状羟胺，其将初始阳离子还原为硝酰基自由基，被氧化为硝酮。