1: 85 percent / CrO3-pyridine / 24 h / Ambient temperature 2: NaBH4, 2 N NaOH / methanol; H2O 3: p-CH3-C6H4-SO3H / benzene / 24 h / Heating View Scheme

toluene-4-sulfonic acid in benzene 24 h; Heating; Yield given. Yields of byproduct given;