Evaluate the following mechanistic statements regarding the conversion of aliphatic alcohols to alky — Haloalkanes and Haloarenes Chemistry Question
Question
Evaluate the following mechanistic statements regarding the conversion of aliphatic alcohols to alkyl halides. Which of them are chemically accurate?
💡 Solution & Explanation
Statement A is correct. $1^\circ$ alcohols lack steric hindrance but form unstable primary carbocations, so the $ZnCl_2$ coordinates with the oxygen to create a better leaving group, allowing pseudo- $S_N2$ displacement. Statement B is false. Neopentyl alcohol possesses extreme steric hindrance blocking $S_N2$ and forces a pathway with a 1,2-methyl shift, yielding a rearranged tertiary product. Statement C is correct. $PCl_5$ reacts rapidly with $-OH$ groups to yield $POCl_3$ and heavy fumes of $HCl$. Statement D is strictly false. The $C-O$ bond in phenol has partial double bond character due to resonance and cannot be displaced by halide ions.