Question

In the given reactions identify the reagent A and reagent B

• A. \( A-\text{CrO}_3 \quad B-\text{CrO}_3\)
• B. \(A-\text{CrO}_3 \quad B-\text{CrO}_2\text{Cl}_2\)
• C. \(A-\text{CrO}_2\text{Cl}_2 \quad B-\text{CrO}_2\text{Cl}_2\)
• D. \(A-\text{CrO}_2\text{Cl}_2 \quad B-\text{CrO}_3\)

Answer 1

The Correct Option is B

Step 1: The reaction starts with toluene, which is oxidized by reagent A (CrO₃) in acetic anhydride (CH₃CO)₂O. This oxidation step is known as the Etard reaction, where toluene is converted into benzylidene diacetate as an intermediate.

Step 2: The intermediate benzylidene diacetate is then treated with reagent B (CrO₂Cl₂), followed by hydrolysis (H₂O⁺) to yield benzaldehyde (C₆H₅CHO).

Thus, the correct reagents are A-CrO₃ and B-CrO₂Cl₂, which is represented by option (2).