Explain the properties and reactions of phenols... - SS2 Chemistry Organic Chemistry II: Alcohols, Phenols, and Ethers Question

Phenols are a class of aromatic compounds that contain a hydroxyl group (-OH) attached to a benzene ring. They exhibit distinct properties and reactivity compared to alcohols. Some key properties and reactions of phenols include:

1.    Acidic Nature: Phenols are more acidic than alcohols due to the stabilisation of the phenoxide ion formed upon deprotonation of the hydroxyl group. Phenols readily donate a proton, making them weak acids. This acidity enables reactions with bases and metal ions. For example, phenols react with strong bases to form phenoxide salts.

2.    Electrophilic Aromatic Substitution: The aromatic ring in phenols undergoes electrophilic aromatic substitution reactions due to the presence of the hydroxyl group, which activates the ring towards electrophilic attack. Common reactions include halogenation, nitration, sulfonation, and Friedel-Crafts acylation or alkylation.

3.    Oxidation Reactions: Phenols can undergo oxidation reactions to form quinones or hydroxyquinones. The oxidation of phenol itself results in the formation of benzoquinone (quinone). Phenols can also undergo further oxidation to form reactive intermediates involved in polymerization reactions.

4.    Esterification: Phenols can undergo esterification reactions with carboxylic acids or acid derivatives to form esters. The reaction involves the replacement of the hydroxyl group by the ester moiety.

Examples of reactions involving phenols include the bromination of phenol, which yields 2,4,6-tribromophenol, and the formation of salicylic acid through the reaction of phenol with acetic anhydride.