Question: Name the following carboxylic acids (when possible, give both a common name and a systematic name).

(a)

(b)

(c)

(d)

(e)

(f)

(a) The IUPAC name is 2-iodo-3-methylpentanoic acid because the iodine group is present at the 2^ndposition, and the methyl groups are present at the third position. The total number of carbons in a chain is5. The common name is $\mathrm{\alpha }-\mathrm{iodo}-\mathrm{\beta }-\mathrm{methylv}\mathrm{aleric}\mathrm{acid}$.

(c) The IUPAC name is 2,3-dinitrobenzoic acid, and the nitro groups are present at the 2^nd and 3^rd positions in the benzene ring. There is no common name.

(d) The IUPAC name is trans-cyclohexane-1,2-dicarboxylic acid. One COOH group is above the plane, and one COOH group is below the plane.The common name is trans-hexahydrophthalic acid.

(e) The IUPAC name is 2-chlorobenzene-1,4-dicarboxylic acid;the chloro group is present at the 2^nd position, and the two COOH groups are present at the 1^st and 4^th positions.The common name is 2-chloroterephthalic acid.

(f) The IUPAC name is 3-methylhexanedioic acid,and one methyl group is present at the 3^rd position.The common name is $\mathrm{\beta }-\mathrm{methyladipic}$.