Which of the following compounds exhibits the highest acidic strength due to the combined influence — GOC and Organic Chemistry Basics Chemistry Question

💡 Solution & Explanation

The ortho-effect states that ortho-substituted benzoic acids are generally more acidic than benzoic acid itself, regardless of the nature of the substituent (electron-donating or withdrawing). In 2,6-dimethylbenzoic acid, the severe steric hindrance forces the carboxyl group out of the plane of the benzene ring (SIR). This prevents the destabilizing $+R$ (cross-conjugation) effect of the ring onto the carboxylate group, maximizing its acidic strength.