Question

The most easily hydrolysed molecule under $S_{N}1$ conditions is

• A. allyl chloride
• B. ethyl chloride
• C. iso-propyl chloride
• D. benzyl chloride

Answer 1

Answer: (D)

$S_{N}1$ mechanism involves formation of cations and the order of stability of carbocations is as
$(C_2{H}_5^{+})(C{H}_3{)}_2\stackrel{+}{C}H<\stackrel{+}{C}{H}_2-CH=C{H}_2<C_6{H}_{5}C{H}_2^{+}$
Thus, benzyl chloride, due to the formation of benzyl carbocation (most stable), readily undergoes hydrolysis by $S_{N}1$ mechanism.