Neet Solved Paper 2015 Question 38
Question: Which of the following is the most correct electron displacement for a nucleophilic reaction to take place?
Options:
A) 
B) 
C) 
D) 
E) None of the above
Show Answer
Answer:
Correct Answer: E
Solution:
Allylic and benzylic halides show high reactivity towards $ S _{N}1 $ reaction further,
due to greater stabilization of allyl and benzyl carbocations intermediates by resonance,
primary allylic and primary benzylic halides show higher reactivity in $ S _{N}1 $ reactions than other simple primary halides.
$ H _3C-\overset{\begin{smallmatrix} H \\ | \end{smallmatrix}}{\mathop{C}}\ =CH-CH _2-Cl\overset{\ }{\longleftrightarrow} $ $ \underset{{2^{o}}\ \text{-allyl}cation}{\mathop{H _3C-\overset{\begin{smallmatrix} H \\ | \end{smallmatrix}}{\mathop{C}}\ -CH=CH _2}}\ \overset{\ }{\longleftrightarrow}\ \underset{{1^{o}}\text{-allyl}cation}{\mathop{H _3C-\overset{\begin{smallmatrix} H \\ | \end{smallmatrix}}{\mathop{C}}\ =CH-\overset{+}{\mathop{C}}\ H _2}}\ $
Hence it undergoes nucleophilic reaction readily.
BETA
