IGNOU BCHET 147 2026 - . Give the resonance structures for the intermediate in the reaction w

Question

. Give the resonance structures for the intermediate in the reaction where electrophile E⁺ attacks on 2-position of pyridine.

10 Jan 2026

Answer :

Word Count : 279

When an electrophile (E^+) attacks the 2-position of pyridine, the reaction involves the formation of a sigma complex (arenium ion), which is the key intermediate. Pyridine is a nitrogen-containing heteroaromatic compound, where the lone pair on nitrogen resides in an sp² orbital perpendicular to the π-system, making the nitrogen electron-withdrawing through the inductive effect. This reduces the electron density at the ortho (2,6) and para (4) positions relative to nitrogen. Despite this, electrophilic substitution at the 2-position can

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