酮Ketone

系统命名用后缀 -one，并标出羰基位次：丙酮 propanone，丁酮 butanone，戊-3-酮 pentan-3-one。酮由仲醇氧化制得：用酸化重铬酸钾加热回流，仲醇被氧化为酮后不再继续氧化。工业上丙酮主要由异丙苯法与苯酚联产。

Systematic names use the suffix -one, with the carbonyl position given: propanone, butanone, pentan-3-one. Ketones are made by oxidising secondary alcohols, heating under reflux with acidified dichromate; the ketone is not oxidised further. Industrially, propanone is made mainly alongside phenol by the cumene process.

酮不易被氧化，与托伦试剂、费林试剂都不反应，据此可与醛区分。酮能发生羰基的亲核加成：被 NaBH₄ 还原为仲醇，与 HCN 加成生成羟基腈，与 2,4-二硝基苯肼生成橙黄色沉淀。含 CH₃CO– 结构的甲基酮与碱性碘溶液反应生成黄色的三碘甲烷沉淀（碘仿反应）。

Ketones resist oxidation and give no reaction with Tollens' reagent or Fehling's solution, which distinguishes them from aldehydes. They undergo nucleophilic addition at the carbonyl: NaBH₄ reduces them to secondary alcohols, HCN adds to give hydroxynitriles, and 2,4-dinitrophenylhydrazine gives an orange-yellow precipitate. Methyl ketones, containing CH₃CO–, react with alkaline iodine to give a yellow precipitate of triiodomethane (the iodoform test).

丙酮是重要的溶剂，能与水和多数有机溶剂互溶，用于去除指甲油、清洗仪器，也是有机玻璃（聚甲基丙烯酸甲酯）的原料。环己酮用于生产尼龙。人体在糖供应不足时会产生丙酮、乙酰乙酸等酮体。

Propanone is an important solvent, miscible with water and most organic solvents; it removes nail varnish, rinses apparatus and is a raw material for poly(methyl methacrylate). Cyclohexanone is used to make nylon. When glucose is scarce, the body produces ketone bodies such as propanone and acetoacetic acid.