Question

The order of reactivity of halides towards $S_N1$ mechanism is

• A. benzyl $>$ allyl $>1^{\circ}>2^{\circ}>3^{\circ}> Me$
• B. Me $>1^{\circ}>2^{\circ}>3^{\circ}>$ allyl $>$ benzyl
• C. $3^{\circ}>2^{\circ}>1^{\circ}> Me > allyl >$ benzyl
• D. benzyl $>$ allyl $>3^{\circ}>2^{\circ}>1^{\circ}> Me$

Answer 1

Answer: (D)

The order of reactivity of halides towards $S_{N} 1$ mechanism is
benzyl $>$ allyl $>3^{\circ}>2^{\circ}>1^{\circ}>$ Me
$S _{ N } 1$ reaction is non-stereospecific and non-stereoselective as the attack of nucleophile is not specific and the products are a mixture of enantiomers.