Discussion
The products A, B & C from the following reactions are respectively
Phenol (C6H5OH) gives A with NaOH, then CO2, H+; gives B with Zn; and gives C with Na2Cr2O7, H2SO4.
Answer: E
A, B and C are 2-hydroxybenzoic acid, benzene and benzoquinone.
A: phenol with NaOH gives sodium phenoxide, which reacts with CO2 (Kolbe's reaction), and acidification gives salicylic acid, that is 2-hydroxybenzoic acid. B: heating phenol with zinc dust removes the oxygen, giving benzene. C: oxidation of phenol with sodium dichromate and sulphuric acid gives benzoquinone.
Aspirin needs a further acetylation of salicylic acid. Salicylaldehyde comes from the Reimer-Tiemann reaction (CHCl3 and NaOH), and quinol is the reduction product of benzoquinone, not its oxidation product. Cyclohexanol and cyclohexanone would need hydrogenation.
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