A chemist desires to synthetically isolate optically pure -chlorobutane starting explicitly from a p — Haloalkanes and Haloarenes Chemistry Question

💡 Solution & Explanation

The chemist requires complete inversion of configuration ($R \rightarrow S$). A) Pure $SOCl_2$ proceeds via $S_Ni$, resulting in total retention. C) Lucas reagent ($HCl/ZnCl_2$) relies heavily on carbocation character, leading to substantial racemisation. D) This mixture generates $HCl$, similar to C. B) The presence of pyridine forcefully directs the $SOCl_2$ reaction away from the internal $S_Ni$ collapse and into a classic intermolecular $S_N2$ displacement by free chloride ions. This rigorous backside attack guarantees the complete Walden inversion required by the chemist.