Question

Most stable product of the following reaction is :

• A.
• B.
• C.
• D.

Answer 1

The Correct Option is B

To determine the most stable product of the given reaction, let's analyze the steps and reagents involved:

1. Reactants and Reagents:
   • The starting material is an alcohol.
   • The first reagent is para-toluenesulfonyl chloride (TsCl) in the presence of pyridine.
   • The second reagent is sodium cyanide (NaCN) in dimethylformamide (DMF).
2. Reaction Steps:
   1. The primary alcoholic group is converted to a good leaving group by reacting with para-toluenesulfonyl chloride (TsCl) in the presence of pyridine. The alcohol is converted to a tosylate intermediate.
   2. The tosylate, being a good leaving group, is subjected to nucleophilic substitution by NaCN. This results in the formation of a nitrile compound.
3. Stereochemistry and Stability:
   • The attack by the cyanide ion (CN⁻) occurs through an S_N2 mechanism, which involves a backside attack. This results in inversion of configuration at the carbon center.
   • The resulting product is a stable nitrile due to the resonance and additional stability provided by the cyanide group.
4. Conclusion: The most stable product is the nitrile formed by the S_N2 mechanism.

Considering these steps, the correct answer is:

The given mechanism provides a clear understanding of the formation of the nitrile product through substitution. This illustration demonstrates the reaction mechanism and product configuration accurately.