Heterocyclic compounds contain atoms other than carbon within the ring structure. Which of the follo — Hydrocarbons Chemistry Question

💡 Solution & Explanation

(A) Pyridine is a 6-membered planar ring with 3 double bonds (6 $\pi$ $e^-$); the nitrogen's lone pair is orthogonal to the $\pi$ system. (B) Pyrrole is a 5-membered planar ring where nitrogen's lone pair is heavily delocalized into the ring to provide the needed 6 $\pi$ electrons. (C) Thiophene similarly utilizes a lone pair on sulfur to attain 6 $\pi$ electrons. (D) Piperidine is a fully saturated, non-planar aliphatic ring, lacking any $\pi$ conjugation entirely.