IUPAC Nomenclature of Carboxylic Acids

Carboxylic acids are organic compounds carrying a carboxyl functional group, -COOH -- structurally the combination of a carbonyl group (>C=O) and a hydroxyl group (-OH) on the SAME carbon, though the -COOH group has its own distinctive reactivity rather than simply behaving as the sum of the two separate groups (Section 12.9). Carboxylic acids may be aliphatic (R-COOH) or aromatic (Ar-COOH) depending on whether the group attached to the carboxylic carbon is an alkyl or an aryl group; some higher aliphatic carboxylic acids (roughly C12 to C18), known as fatty acids, occur naturally as esters of glycerol in fats and oils. IUPAC nomenclature follows the same pattern as for aldehydes (Section 12.1): find the longest chain containing the -COOH carbon (always C1, since -COOH must sit at a chain end), and replace the alkane's '-e' ending with '-oic acid'. For a dicarboxylic …