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Consider the following reaction sequence: n-heptane Cr₂O₃, 773 K , 10-20 atm A CrO₃, (CH₃CO)₂O, 273-283 K B H₃O^+, C Conc. NaOH D + E The intermediates B and C are respectively:

Options

  1. AB is Benzoic anhydride, C is Benzoic acid
  2. BB is Benzylidene diacetate, C is Benzaldehyde
  3. CB is Benzal chloride, C is Benzaldehyde
  4. DB is Benzylidene diacetate, C is Benzyl alcohol

Correct answer

B. B is Benzylidene diacetate, C is Benzaldehyde

Step-by-step solution

The aromatization of n-heptane over Cr₂O₃ at 773 K and high pressure yields toluene ( A ). Toluene is oxidized by chromic oxide ( CrO₃ ) in the presence of acetic anhydride. The reaction stops at the aldehyde stage because the intermediate formed is a gem-diacetate, specifically benzylidene diacetate ( B ), which is stable under the reaction conditions and prevents further oxidation to benzoic acid. Upon acid hydrolysis ( H₃O^+, ), the benzylidene diacetate ( B ) is converted to benzaldehyde ( C ). Benzaldehyde the

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