Question

Which correct sequence of reactions are applied to achieve the following transformation? \[ \text{Benzoyl Chloride} \xrightarrow{H_2, \text{Pd-BaSO}_4} \xrightarrow{\text{dil. NaOH}} \text{Cinnamaldehyde} \] Choose the correct sequence of reactions from the options given below:

• A. Bouveault-Blanc's reduction followed by Kolbe-Schmidt's reaction
• B. Rosenmund's reduction followed by Claisen-Schmidt's reaction
• C. Bouveault-Blanc's reduction followed by Claisen-Schmidt's reaction
• D. Rosenmund's reduction followed by Perkin's reaction

Hint:

The Rosenmund reduction selectively reduces acyl chlorides to aldehydes, and the Claisen-Schmidt reaction forms cinnamaldehyde.

Answer 1

The Correct Option is B

Step 1: Rosenmund's Reduction.
The reduction of benzoyl chloride using hydrogen (\(H_2\)) over palladium on barium sulfate (\(Pd-BaSO_4\)) is called Rosenmund's reduction. This reaction selectively reduces the acyl group to an aldehyde, yielding benzaldehyde.

Step 2: Claisen-Schmidt's Reaction.
The reaction of benzaldehyde with a base (like dilute NaOH) leads to the Claisen-Schmidt condensation, where it reacts with acetaldehyde to form cinnamaldehyde.

Step 3: Conclusion.
Thus, the correct sequence involves Rosenmund's reduction followed by the Claisen-Schmidt reaction.

Final Answer: \[ \boxed{\text{(2) Rosenmund's reduction followed by Claisen-Schmidt's reaction}} \]