Question

Which of the following heterocyclic compounds would have aromatic character?

• A.
• B.
• C.
• D.

Answer 1

The correct option is D

For a compound to be aromatic,
(i) It should be cyclic
(ii) It should be planar
(iii) It should have extended conjugation
(iv) It should have (4n+2) $\pi$ electrons
Lacking any one of the above requirement, the compound cannot be an aromatic.
Compound (a) and (b) have 8 $\pi$ electrons so they are not aromatic.
Compound (c) has 8 $\pi$ electrons. Hence, it is antiaromatic in nature.


Compound (d) obeys all the rules with 6$\pi$ electrons. Hence, it is an aromatic compound.