Question

The correct sequence of reagents for the preparation of Q and R is:

• A. (i) Cr₂O₃, 770K,20atm (ii) CrO₂Cl₂,H₃O⁺; (iii) NaOH; (iv) H₃O⁺
• B. (i) Mo₂O₃,Δ; (ii) CrO₂Cl₂,H₃O⁺; (iii) NaOH; (iv) H₃O⁺
• C. (i) CrO₂Cl₂,H₃O⁺; (ii) Cr₂O₃,770K,20atm;(iii) NaOH; (iv) H₃O⁺
• D. (i) KMnO_4,OH⁻; (ii) Mo₂O₃,Δ; (iii) NaOH; (iv) H₃O⁺

Answer 1

The Correct Option is A

Answer 2

The reaction sequence involves:
1. Step 1: Oxidation of benzene to benzoquinone using CrO$_3$ at 770 K and 20 atm.
2. Step 2: Formation of phenol by further oxidation with CrO$_2$Cl$_2$ in acidic medium.
3. Step 3: Neutralization with NaOH to form phenoxide ion.
4. Step 4: Acidification with H$_3$O$^+$ to yield phenol. In the preparation of phenol from benzene, the use of CrO$_3$ and CrO$_2$Cl$_2$ ensures selective oxidation steps. Acidic and basic conditions aid in subsequent transformations.