Question

Among the following, the compound which is wrongly named is:

1. 2-chloropentanoic acid
2. 2-methylpent-2-en-5- oic acid
3. hex-3-en-2-one
4. 4-methylpentanal

Answer 1

The compound that is wrongly named among the given options is 2-methylpent-2-en-5-oic acid.The correct option is (2).

Step-by-step explanation:

The compound that is wrongly named among the given options is 2-methylpent-2-en-5-oic acid.

To determine the correct name of a compound, we need to follow the IUPAC nomenclature rules.

1. The name 2-chloropentanoic acid is correct. It indicates that there is a chlorine atom attached to the second carbon of the pentanoic acid molecule.
2. The name hex-3-en-2-one is correct. It indicates that there is a double bond between the third and fourth carbon atoms, and a ketone functional group is present at the second carbon atom.
3. The name 4-methylpentanal is correct. It indicates that there is a methyl group attached to the fourth carbon atom of the pentanal molecule.
4. The name 2-methylpent-2-en-5-oic acid is wrongly named. According to the IUPAC rules, the locant for the carboxylic acid group should be the lowest possible number. In this case, it should be located at the first carbon atom, not the fifth carbon atom. Additionally, the numbering of the double bond and the methyl group should be such that the lower locant is assigned to the double bond, followed by the methyl group.

Therefore, the 2-methylpent-2-en-5-oic acid is the compound that is wrongly named among the given options.