Question

Which of the following is not aromatic?

• A. \( \text{Thiophene} \)
• B. \( \text{Dioxane} \)
• C. \( \text{Pyrrole} \)
• D. \( \text{Isoxazole} \)

Hint:

Aromatic compounds follow Hückel’s rule, requiring (4n + 2) π-electrons for stability.

Answer 1

The Correct Option is B

Dioxane is a non-aromatic compound because it lacks a conjugated π-system and does not follow Hückel’s rule. On the other hand, thiophene, pyrrole, and isoxazole are aromatic due to the presence of conjugated electron systems. Aromaticity arises when delocalized electrons form a stable, cyclic structure.