Concept:Identify the longest carbon chain and number it so substituents get the lowest locants.
Explanation:The longest continuous chain contains four carbon atoms, so the parent chain is butane.
The substituents attached to this chain are a chlorine atom and a methyl group.
Number the chain from the end nearer the substituted carbon to obtain the lowest locants.
The substituted carbon is carbon
2, so the locants are
2 for both substituents.
Arrange the substituent names alphabetically: “chloro” comes before “methyl.”
Therefore, the correct IUPAC name is 2-chloro-2-methylbutane.
Answer:D. 2-chloro-2-methylbutane
