Carboxylic acids, including fatty acids, are abundant in nature. They serve as starting materials for various organic compounds such as anhydrides, esters, acid chlorides, and amides.

Carboxylic acids can be classified as aliphatic (RCOOH) or aromatic (ArCOOH) based on whether the attached group is alkyl or aryl. Fatty acids, esters of glycerol, are examples of higher aliphatic carboxylic acids.

Carboxylic acids contain the carboxyl functional group, -COOH, which consists of a carbonyl group attached to a hydroxyl group.

Aldehydes and ketones serve as solvents, starting materials, and reagents in the chemical industry. Examples include formaldehyde used in preserving biological specimens and making bakelite, acetaldehyde in the production of acetic acid and polymers, and benzaldehyde in perfumery and dye ...

Aromatic aldehydes and ketones undergo electrophilic substitution on the aromatic ring, where the carbonyl group acts as a deactivating and meta-directing group.