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Chemistry LibreTexts

15.3: The Formation of Carboxylic Acids

Skills to Develop

  • To describe the preparation of carboxylic acids.

As we noted previously, the oxidation of aldehydes or primary alcohols forms carboxylic acids:

primary alcohol.jpg

In the presence of an oxidizing agent, ethanol is oxidized to acetaldehyde, which is then oxidized to acetic acid.

ethanol.jpg

This process also occurs in the liver, where enzymes catalyze the oxidation of ethanol to acetic acid.

\[\mathrm{CH_3CH_2OH \underset{oxidizing\: agent}{\xrightarrow{alcohol\: dehydrogenase}} CH_3CHO \underset{oxidizing\: agent}{\xrightarrow{alcohol\: dehydrogenase}} CH_3COOH\%}\]

Acetic acid can be further oxidized to carbon dioxide and water.

Summary

Whether in the laboratory or in the body, the oxidation of aldehydes or primary alcohols forms carboxylic acids.

Concept Review Exercises

  1. Caproic acid (hexanoic acid) can be prepared in an oxidation reaction from

    1. what alcohol?
    2. what aldehyde?
  2. Give the structures of the aldehyde and the carboxylic acid formed by the oxidation of isobutyl alcohol [(CH3)2CHCH2OH].

Answers

  1.  

    1. CH3CH2CH2CH2CH2CH2OH
    2. CH3CH2CH2CH2CH2CHO
  2. 2.jpg

 

Exercises

  1. Caprylic acid (octanoic acid) can be prepared in an oxidation reaction from

    1. what alcohol?
    2. what aldehyde?
  2. Give the structures of the aldehyde and the carboxylic acid formed by the oxidation of 1,4-butanediol (HOCH2CH2CH2CH2OH).

Answer

  1.  

    1. CH3CH2CH2CH2CH2CH2CH2CH2OH
    2. CH3CH2CH2CH2CH2CH2CH2CHO