Which of the following alkyl halides is the most reactive in solvolysis of alkyl chlorides in 50% aqueous ethanol?

Options

A.
B.
C.
D.

Answer

D

Explanation

Solvolysis is just the substitution reaction in which solvent molecules work as nucleophile to give substitution product. In general, solvent molecules are neutral, so, are weak nucleophiles, in these reaction conditions `S_N2` reaction is very slow but `S_N1` could be very fast if stable carbocation is formed during the reaction.
Thus for solvolysis, `S_N1` reaction conditions should be considered. Out of the given options, compound in option (D) produces `3^(@)` allylic carbocation which is most stable, so, solvolysis in this case is fastest.