Question

Name of the compound given below is :

• A. 3-methyl-4-ethyloctane
• B. 2,3-diethylheptane
• C. 5-ethyl-6-methyloctane
• D. 4-ethyl-3-methyloctane

Hint:

Alphabetical order ignores prefixes like di-, tri-, but ethyl comes before methyl.

Answer 1

The Correct Option is D

Concept: IUPAC naming rules:
• Choose longest carbon chain
• Number to give lowest locants
• Arrange substituents alphabetically

Step 1: Find the longest chain. The longest continuous carbon chain contains 8 carbons → octane.

Step 2: Number the chain. Number from the end that gives the lowest locants to substituents. Methyl at C-3, ethyl at C-4 (not C-6 and C-5).

Step 3: Arrange substituents alphabetically. Ethyl comes before methyl. \[ \Rightarrow 4\text{-ethyl-3-methyloctane} \]