Question

${\mathrm{S}}_{\mathrm{N}}1$ reaction of alkyl halides leads to:

• A. retention of configuration
• B. racemization
• C. inversion of configuration
• D. None of these

Answer 1

The correct option is B

racemization

The correct option is (B):

Explanation for the correct answer:

SN1 reaction:-

• It is a nucleophilic substitution reaction, in which stable carbocation is formed.
• Rate of SN1 reaction is directly proportional to the carbocation stability in the reaction.
• There is basically a two step reaction in this reaction and the intermediated formed in this reaction is basically a carbocation.
• When a nucleophile attacks the carbocation in the reaction, two products would be formed.
• One product will have the same configuration as there before the reaction and the other formed product will have an inverted configuration which will lead to partial racemization.

So, an example for this reaction:

Step 1:

• In the first step in this reaction, there would be cleavage of C-Br bond
• This will lead to the removal of leaving group and formation of carbocation

Step 2:

• Now the stable carbocation would be reacted by the nucleophile.
• Nucleophile will attack the central carbon which is the most stable

Step 3:

• As a last step deprotonation will take place
• And there will be formation of alkyl chloride.

Therefore, the correct option is (B): racemization