氧化
醇 → 酮：查看反应物、产物、反应条件与来源依据，探索相关转化和合成路径。
- 试剂
- 酸化的 K2Cr2O7
- 条件
- 加热回流
- 反应类别
- 氧化
- 方程式
- R-CHOH-R' + [O] -> R-CO-R' + H2O
概览
仲醇氧化生成酮。
转化
- 方程式
- R-CHOH-R' + [O] -> R-CO-R' + H2O
- 试剂
- 酸化的 K2Cr2O7
- 反应环境
- 加热回流
- 反应类别
- 氧化
- 机理
- 氧化
- Evidence level
- 教材核心内容
参考步骤
Microscale reaction check: alcohol oxidation
Propan-2-ol + acidified dichromate(VI)
物料与用量
- Potassium dichromate(VI) solution — 0.1 mol dm⁻³, about 2 cm³
- Sulfuric acid — 1 mol dm⁻³, about 1 cm³
- Propan-2-ol — 2 drops for the reaction well
- One unreacted acidified dichromate well — control
仪器装置
- 24-well plate
- 5–10 cm³ measuring cylinder
- Glass rod
- Dropping pipettes
- Eye protection
实验步骤
- Mix approximately 2 cm³ of 0.1 mol dm⁻³ potassium dichromate(VI) with about 1 cm³ of 1 mol dm⁻³ sulfuric acid.
- Place 10 drops of the acidified dichromate mixture into the reaction well and 10 drops into a separate control well.
- Add 2 drops of propan-2-ol to the reaction well only.
- Observe the reaction and control over 15 minutes.
关键控制条件
- Potassium dichromate(VI) is toxic and a chromium(VI) hazard; use the specified microscale quantities, eye protection and the institution's disposal procedure.
- This method distinguishes reactivity; it must not be presented as a preparative ketone isolation.
实验技术
Controlled comparison of reaction times
Compare a visible change while keeping variables other than the one under study consistent.
装置设置
- Use equal concentrations, volumes and mixing methods, and equilibrate samples at the same temperature.
- Define the visible endpoint before starting and record repeated measurements.
操作检查
- Precipitation time includes mixing and detection thresholds; its inverse is only a relative-rate proxy under matched conditions.
- Do not compare different carbon skeletons when isolating the effect of halogen identity.
Infrared evidence for functional-group change
Use functional-group absorptions and the fingerprint pattern to test a proposed transformation.
装置设置
- Check sample identity, background and axis units before assigning absorptions.
- Compare the starting material and product: oxidation may introduce C=O while removing an alcohol O–H feature.
操作检查
- Water, solvent and unreacted substrate can contribute bands.
- A carbonyl band alone does not distinguish every aldehyde, ketone, acid and ester. Use reference data and complementary evidence; no simulated trace is a measurement.
底物范围
- 适用范围
- 仲醇可氧化为酮。
- 来源说明
- 叔醇不属于此路线，因为在所列标准条件下不发生这种氧化。
相关反应
- Chlorination: Alcohols → Chloroalkanes
醇可转化为氯代烷，为后续取代反应引入更易离去的基团。
- Chlorination with thionyl chloride: Alcohols → Chloroalkanes
氯化亚砜将醇转化为氯代烷，同时生成二氧化硫和氯化氢。
- Bromination: Alcohols → Bromoalkanes
在溴化物和酸的作用下，醇转化为溴代烷。
- Iodination: Alcohols → Iodoalkanes
在碘和红磷的作用下，醇转化为碘代烷。
- Hydrolysis: Chloroalkanes → Alcohols
氢氧根可取代 C-Cl 中的氯，形成醇。
- Hydrolysis: Bromoalkanes → Alcohols
氢氧根可取代 C-Br 中的溴，形成醇。
- Hydrolysis: Iodoalkanes → Alcohols
氢氧根可取代 C-I 中的碘，形成醇。
- Cyanohydrin formation: Ketones → Hydroxynitriles
氰根与酮加成生成羟基腈，为有机反应网络增加另一条羰基路线。
- Oxidation: Alcohols → Aldehydes
伯醇经受控氧化可生成醛。
- Oxidation: Alcohols → Carboxylic acids
伯醇充分氧化生成羧酸。
- Oxidation: Secondary alcohols → Ketones
仲醇氧化生成酮。
- Reduction: Ketones → Secondary alcohols
酮还原生成仲醇。
- Hydration: Alkenes → Alcohols
催化水合将烯烃转化为醇。
- Dehydration: Alcohols → Alkenes
脱水将醇转化为烯烃。
- Esterification co reactant: Alcohols → Esters
醇与羧酸结合形成酯。
- Hydrolysis co product: Esters → Alcohols
酯水解也会重新生成相应的醇。
参考文献
- Pearson Edexcel Level 3 Advanced GCE in Chemistry specificationPearson Education Limited · Pearson qualifications · 2024
Supports the textbook-core organic reaction routes used for displayed route and mechanism content.
- A microscale oxidation of alcoholsRoyal Society of Chemistry and Nuffield Foundation · RSC Education
Provides a controlled microscale acidified dichromate reaction check for primary, secondary and tertiary alcohols; products are not isolated.
- Rates of hydrolysis: practical videos for 16–18 studentsRoyal Society of Chemistry · RSC Education
Water is the nucleophile in the silver-nitrate comparison, and silver-halide precipitation measures released halide indirectly.
- Infrared spectroscopy: introductionRoyal Society of Chemistry · RSC Education
Molecular vibrations, functional-group absorptions and fingerprint comparison; no fabricated sample spectra.