Question

Most stable product of the following reaction is:

• A.
• B.
• C.
• D.

Answer 1

The Correct Option is B

The given reaction involves a two-step process where an alcohol reacts to form a more stable product. Let's analyze the reaction step-by-step:

1. The reaction starts with the treatment of an alcohol with \(\text{TsCl (p-toluenesulfonyl chloride)}\) in pyridine. This step results in the formation of a tosylate ester, converting the -OH group into a better leaving group without changing the configuration at the chiral center.
2. In the second step, the resulting tosylate compound is treated with \(\text{NaCN in DMF (dimethylformamide)}\). This is a nucleophilic substitution reaction where the CN^- ion, a good nucleophile, attacks the tosylate. The configuration is inverted due to the backside attack, as per the S_N2 mechanism.
3. The final product is a nitrile, formed after the substitution of the tosyl group with the cyanide ion. Considering the stereochemistry, the product configuration is inverted relative to the starting alcohol due to the S_N2 reaction.

The most stable product from this reaction sequence is represented by the following image:

Conclusion: The correct and most stable product results from the nucleophilic substitution where the cyanide ion replaces the tosyl group. The stereochemistry of the final product will be opposite to that of the initial substrate due to the S_N2 mechanism. Therefore, the correct answer corresponds to the structure shown in the image above.

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