Like the other functional groups, many carboxylic acids are also named by their common names.
Make note of the common prefixes used in the examples in Figure 8.2.
Figure 8.2. IUPAC and Common Names of Carboxylic AcidsMCAT EXPERTISE
The same common-name prefixes are used for both aldehydes and carboxylic acids: form–
for one carbon, acet– for two, and propion– for three.Cyclic carboxylic acids are named by listing the cycloalkane with the suffix carboxylic acid. Salts of
carboxylic acids are named beginning with the cation, followed by the name of the acid with the
ending –oate replacing –oic acid. Typical examples are shown in Figure 8.3.
Figure 8.3. Cyclic Carboxylic Acid and Carboxylic Acid SaltFinally, dicarboxylic acids, which have a carboxylic acid group on each end of the molecule, are
common in biological systems. The smallest dicarboxylic acid is oxalic acid, with two carbons. The
next five straight-chain dicarboxylic acids are malonic, succinic, glutaric, adipic, and pimelic acids.
Their IUPAC names have the suffix –dioic acid: ethanedioic acid, propanedioic acid, butanedioic
acid, pentanedioic acid, hexanedioic acid, and heptanedioic acid. Figure 8.4 shows several
examples.