Oxidation

Overview

Controlled oxidation of a primary alcohol gives an aldehyde.

Transformation

Alcohols → Aldehydes

Equation

R-CH2OH + [O] -> R-CHO + H2O

Reagents

acidified K2Cr2O7

Environment

heat gently and distil the aldehyde as it forms

Reaction class

oxidation

Mechanism

oxidation

Evidence level

textbook core

Scope and limitations

Scope

Primary alcohols can be oxidised to aldehydes when the aldehyde is distilled from the oxidising mixture.

Limitations

This generic alcohol-family route records the primary-alcohol branch; substrate class is stated in the scope.

Related reactions

• Chlorination: Alcohols → Chloroalkanes

  Alcohols can be converted into chloroalkanes to create a better leaving group for downstream substitution.

• Chlorination with thionyl chloride: Alcohols → Chloroalkanes

  Thionyl chloride converts alcohols into chloroalkanes with sulfur dioxide and hydrogen chloride as by-products.

• Bromination: Alcohols → Bromoalkanes

  Bromide and acid conditions convert alcohols into bromoalkanes.

• Iodination: Alcohols → Iodoalkanes

  Iodine and red phosphorus conditions convert alcohols into iodoalkanes.

• Hydrolysis: Chloroalkanes → Alcohols

  The C-Cl bond can be displaced by hydroxide to form an alcohol.

• Hydrolysis: Bromoalkanes → Alcohols

  The C-Br bond can be displaced by hydroxide to form an alcohol.

• Hydrolysis: Iodoalkanes → Alcohols

  The C-I bond can be displaced by hydroxide to form an alcohol.

• Cyanohydrin formation: Aldehydes → Hydroxynitriles

  Cyanide addition to an aldehyde forms a hydroxynitrile, giving a carbonyl-route analogue of the nitrile chain-extension motif.

• Oxidation: Alcohols → Ketones

  Oxidation of a secondary alcohol gives a ketone.

• Oxidation: Alcohols → Carboxylic acids

  Full oxidation of a primary alcohol gives a carboxylic acid.

• Controlled oxidation: Primary alcohols → Aldehydes

  Controlled oxidation of a primary alcohol gives an aldehyde.

• Reduction: Aldehydes → Primary alcohols

  Reduction of an aldehyde gives a primary alcohol.

• Oxidation: Aldehydes → Carboxylic acids

  Oxidation of an aldehyde gives a carboxylic acid.

• Hydration: Alkenes → Alcohols

  Catalytic hydration converts alkenes into alcohols.

• Dehydration: Alcohols → Alkenes

  Dehydration converts alcohols into alkenes.

• Esterification co reactant: Alcohols → Esters

  Alcohols combine with carboxylic acids to form esters.

References

1. 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.