If pyridine is added to the reaction mixture of an alcohol and thionyl chloride (), how does it chan — Reaction Mechanism Chemistry Question

💡 Solution & Explanation

Pyridine acts as a base to neutralize the $HCl$ byproduct, freeing the $Cl^-$ ion. The free $Cl^-$ acts as an external nucleophile, attacking from the backside via an $S_N2$ pathway to cause stereochemical inversion.