Question

What is IUPAC name of following compound?

• A. 3-Hydroxy-1-methylcyclopentane
• B. 3-Methylcyclopentanol
• C. 1-Methylcyclopentan-3-ol
• D. 3-Methylpentan-1-ol

Hint:

- –OH always gets priority in numbering - Use "cyclo" prefix for ring compounds - Number ring to minimize locants

Answer 1

The Correct Option is C

Concept:
In cyclic compounds:
• Functional group (–OH) gets priority in numbering
• Parent chain is the ring if it has more carbons than substituent
• Naming format: substituent + cycloalkane + suffix (-ol)

Step 1: Identify parent chain
The structure is a five-membered ring $\Rightarrow$ cyclopentane.

Step 2: Identify functional group
Presence of –OH group $\Rightarrow$ suffix = -ol

Step 3: Number the ring
Numbering is done such that:
• –OH gets the lowest possible number Thus, –OH is at position 3.

Step 4: Identify substituent
There is a methyl group at position 1.

Step 5: Write IUPAC name
\[ \text{1-Methylcyclopentan-3-ol} \]