Question

Question: Give an IUPAC and common name for each of the following naturally occurring carboxylic acids: (a) ${\mathbf{CH}}_{\mathbf{3}}\mathbf{CH}\left(\mathrm{OH}\right){\mathbf{CO}}_{\mathbf{2}}\mathbf{H}$(lactic acid); (b) ${\mathbf{HOCH}}_{\mathbf{2}}{\mathbf{CH}}_{\mathbf{2}}\mathbf{C}\left(\mathrm{OH}\right)\left({\mathrm{CH}}_3\right){\mathbf{CH}}_{\mathbf{2}}{\mathbf{CO}}_{\mathbf{2}}\mathbf{H}$ (mevalonic acid).

Short answer

Answer

1. 2-Hydroxypropanoic acid (lactic acid)
2. 3,5-Dihydroxy-3-methylpentanoic acid (mevalonic acid)

Step-by-step solution

Step-by-Step SolutionStep 1: IUPAC names

IUPAC nomenclature is used in the naming of organic compounds.It comprises a set of rules to be followed while naming a compound.

The IUPAC name of a compound includes the name of the parent chain (longest chain of atoms), along with the name and position of the substituents present in it, with everything written in alphabetical order.

The atoms in a parent chain are numbered, such that the functional groups or the substituents get the least possible number.

IUPAC name of compound A

The structure of compound A is shown below:

Lactic acid

The given compound consists of three carbon atoms and a carboxylic acid functional group.

The second carbon consists of a hydroxyl group (OH) as a substituent.

Therefore, the IUPAC name of the given compound is 2-hydroxypropanoic acid.

The common name of the given compound is lactic acid.

IUPAC name of compound B

Mevalonic acid

The given compound consists of five carbon atoms and a carboxylic acid functional group.

The second carbon consists of a hydroxyl group (OH) as a substituent.

Therefore, the IUPAC name of the given compound is 3,5-dihydroxy-3-methylpentanoic acid.

The common name of the given compound is mevalonic acid.