Question

Rosenmund reduction is used to convert acyl chlorides into:

• A. Alcohols
• B. Carboxylic acids
• C. Aldehydes
• D. Ketones

Hint:

Remember the specific reagent for Rosenmund: \( Pd-BaSO_4 \). It is the standard method to "stop" the reduction at the aldehyde stage.

Answer 1

The Correct Option is C

Step 1: Understanding the Question:
The question asks for the organic product formed when an acyl chloride (acid chloride) undergoes Rosenmund reduction.
Step 2: Key Formula or Approach:
Identify the specific reagents and reaction conditions: Hydrogen gas (\( H_2 \)) in the presence of Palladium (\( Pd \)) catalyst supported on Barium Sulfate (\( BaSO_4 \)).
Step 3: Detailed Explanation:
Rosenmund reduction is a catalytic hydrogenation process.
The general reaction is:
\[ R-COCl + H_2 \xrightarrow{Pd/BaSO_4} R-CHO + HCl \]
1. The Palladium catalyst facilitates the addition of hydrogen.
2. Barium sulfate (\( BaSO_4 \)) acts as a "catalytic poison" to reduce the activity of Palladium.
3. This poisoning is crucial because it prevents the newly formed aldehyde from being further reduced to a primary alcohol.
Step 4: Final Answer:
The reduction of acyl chlorides via the Rosenmund reaction yields aldehydes.