Question

Write the structures and IUPAC names of the following compounds.
(a) Adipic acid
(b) $\alpha$ -methyl butyraldehyde

Answer 1

The molecular formula of adipic acid is ${C_6}{H_{10}}{O_4}$ and the molecular formula of the $\alpha$ -methyl butyraldehyde is ${C_5}{H_{10}}O$. By the name itself it can be assumed that the adipic acid contains carboxylic acid functional group in its structure and $\alpha$ -methyl butyraldehyde contains aldehyde functional group in its structure.

Complete step by step answer:
(a) Adipic acid is an organic compound with molecular formula of adipic acid is ${C_6}{H_{10}}{O_4}$. Adipic acid is white crystalline solid which is insoluble in water.
The structure of adipic acid is shown below.

The parent chain of the adipic acid consists of 6 carbon atoms so the hydrocarbon name will be hexane. In the 1st and 6th position of the hydrocarbon chain carboxylic acid functional group is attached (COOH), so the suffix will be given as –oic. As two carboxylic groups are present then it will be dioic. The resulting IUPAC name of the adipic acid is hexanedioic acid.
(b) $\alpha$ -methyl butyraldehyde: The molecular formula of ${C_5}{H_{10}}O$.
The structure of $\alpha$ -methyl butyraldehyde is shown below.

In the structure, the parent chain consists of 4 carbon atoms so the hydrocarbon chain will be butane, in the second position methyl group is attached and in the first position aldehyde group is present. The resulting IUPAC name of $\alpha$ -methyl butyraldehyde is 2-methyl butyraldehyde.

Note:
Make sure that the numbering of the hydrocarbon chain is done from where the functional group is attached. The IUPAC name of $\alpha$ -methyl butyraldehyde can also be 2-methyl butanal as for the aldehyde group the suffix is given as –al.