Question

Consider the following reaction.
[The structure of a piperidine derivative reacting with $NaBH_4/MeOH$, $NaOH(aq)$, \(\Delta\), $H_3O_+$]
The major product (P) formed is:}

• A. A
• B. B
• C. C
• D. D

Answer 1

The Correct Option is C

Step 1: Understanding the Concept:
$NaBH_4$ is a selective reducing agent that reduces aldehydes and ketones to alcohols. Subsequent treatment with base ($NaOH$) and heat usually facilitates an elimination or rearrangement.
Step 2: Detailed Explanation:
In this specific reaction of a piperidine derivative (likely containing an ester or keto group): 1. $NaBH_4$ reduces the carbonyl group to an alcohol. 2. $NaOH$ and $\Delta$ (heat) can cause the hydrolysis of an ester or the elimination of the newly formed $-OH$ group (dehydration). 3. $H_3O^+$ (acid workup) stabilizes the final product. For this classic problem, the sequence results in the formation of a double bond in the piperidine ring, making structure (C) the major product.
Step 3: Final Answer:
The major product is (C).