Which of the following is not an aromatic compound?
The correct option is B Aromatic compound → should be cyclic, planar and have delocalization of π electrons. They should obey (4n+2)πe− rule. Compound (a), (c) and (d) has 6 π electrons which obey huckel rule and they are aromatic in nature. Compound (b) has no delocalisation of electrons due to presence of sp3 carbon. Hence, it violates huckel rule and it is a non-aromatic compound.