Question

The correct IUPAC name of the following compound is: \[ {CH3-CH2-CH(CH3)-CH2-CH(CH3)-CH2-CH3} \]

• A. 3-methyl-5-ethylhexane
• B. 3-ethyl-5-methylheptane
• C. 3,5-dimethylheptane
• D. 2,4-diethylhexane

Hint:

Choose the longest chain as parent and number it to give substituents the lowest possible locants.

Answer 1

The Correct Option is C

Step 1: Identify the longest carbon chain. 
The given structure is: \[ {CH3-CH2-CH(CH3)-CH2-CH(CH3)-CH2-CH3} \] The longest continuous chain contains: \[ 7 \] carbon atoms. So the parent hydrocarbon is: \[ \text{heptane}. \] 

Step 2: Identify substituents. 
There are two methyl groups: \[{-CH3} \] One methyl group is attached to carbon \(3\). The other methyl group is attached to carbon \(5\). 

Step 3: Number the chain. 
Numbering from either end gives: \[ 3,5 \] So the locants are: \[ 3,5 \] 

Step 4: Write the IUPAC name. 
Since there are two methyl substituents, we use: \[ \text{dimethyl}. \] Therefore, the IUPAC name is: \[ \text{3,5-dimethylheptane}. \]