Alcohols, Phenols and Ethers

About this unit

Alcohols, phenols and ethers are oxygen-containing organic compounds. Alcohols have –OH on an sp³ carbon, phenols have –OH directly on a benzene ring, and ethers have an oxygen joining two carbon groups (R–O–R′). They include everyday substances such as ethanol, antiseptics and solvents. The unit covers naming, preparation, physical properties and the reactions that make these compounds important in synthesis and industry.

Key ideas

• Classification: mono-, di- and trihydric alcohols; 1°, 2° and 3° alcohols; simple and mixed ethers.
• Preparation of alcohols from alkenes, carbonyl compounds and Grignard reagents; preparation of phenol including the cumene process.
• Hydrogen bonding and its effect on boiling point and solubility.
• Acidity of alcohols and phenols and the effect of substituents.
• Reactions: esterification, Lucas test, dehydration, oxidation, electrophilic substitution in phenol, Kolbe and Reimer–Tiemann reactions.
• Williamson synthesis and cleavage of ethers by HI.

How to prepare

Make reaction charts showing each reagent and product, and practise converting one compound into another in two or three steps. Learn the acidity order of alcohols, phenol and substituted phenols with reasons. Know the tests that distinguish 1°, 2° and 3° alcohols and that distinguish phenol from alcohols.