Question

Which of the following compound is expected to be aromatic?

• A.
• B.
• C.
• D.

Answer 1

The correct option is D

Huckle's rule: It states that if a cyclic, planar molecule has 4n + 2 $\pi$ delocalised electrons, it is considered as an aromatic compound.
It has $6\pi$ electrons and its cyclic and planar so it obeys Huckel rule. Hence it is an aromatic compound.

(a) and (b) are antiaromatic compounds because they have 4n $\pi$ electrons
(c) It is a non-aromatic compound because it has a $s{p}^3$ carbon, so it wont be a planar molecule.