Question

The major product formed in the following reaction is

 

• A. A
• B. B
• C. C
• D. D

Hint:

Under basic conditions, conjugated aldehydes or ketones react with CN$^-$ at the $\beta$-position (Michael addition), yielding $\beta$-cyano carbonyl products.

Answer 1

The Correct Option is C

Step 1: Reaction type identification.
This reaction involves an **HCN/KCN system** at high temperature (160°C), which promotes **Strecker-type cyanohydrin formation followed by rearrangement** or **conjugate addition (Michael addition)** depending on the substrate.
Step 2: Substrate analysis.
The substrate is an $\alpha,\beta$-unsaturated aldehyde (enone-type). Under basic HCN/KCN conditions, nucleophilic addition of CN$^-$ occurs at the **$\beta$-carbon** via Michael addition.
Step 3: Product formation.
The cyanide adds to the $\beta$-position, generating a **$\beta$-cyano carbonyl compound**.
Thus, the product contains both a carbonyl and a nitrile group separated by one carbon atom.
Step 4: Conclusion.
The major product is the $\beta$-cyano aldehyde (Option A).