Question

Which among the following is an aromatic aldehyde ?

• A.

  

• B.

  

• C.

  

• D.

  

Hint:

In an aromatic aldehyde the CHO group is bonded directly to the benzene ring.

Answer 1

The Correct Option is D

Step 1: Understand the concept
An aromatic aldehyde has the formyl group (-CHO) attached directly to a carbon of the benzene ring. The simplest example is benzaldehyde, \(\text{C}_6\text{H}_5\text{CHO}\).

Step 2: Look at option (A)
The structure is a benzene ring joined to a \(\text{CH}_2\) group, which then carries the CHO. This is phenylacetaldehyde. The CHO is on the side chain, not on the ring, so it does not fit the definition.

Step 3: Look at options (B) and (C)
Option (B) is a benzene ring joined to a \(\text{CH=CH-CHO}\) chain (cinnamaldehyde), so the CHO is again on the side chain. Option (C) is a saturated cyclohexane ring with a CHO group, an alicyclic aldehyde with no aromatic ring at all.

Step 4: Look at option (D)
Option (D) is a benzene ring with a CHO group on one ring carbon and a methyl group on the neighbouring carbon. This is 2-methylbenzaldehyde, with the CHO directly on the ring. So it is the aromatic aldehyde.

Final Answer:
The CHO group is attached directly to the ring in option (D). This is option (D). \[ \boxed{\text{(D) }\text{2-Methylbenzaldehyde}} \]