manganese(IV) oxide in ethyl acetate T=20°C;

1: sulfuric acid / 3 h / |Reflux 2: diisobutylaluminium hydride / toluene; tetrahydrofuran / -10 - 20 °C 3: manganese(IV) oxide / ethyl acetate / 20 °C View Scheme

1.1: sodium hydroxide / water / 1 h / 50 °C 1.2: 1 h / |Cooling with ice 1.3: 20 °C / |Cooling with ice 2.1: sulfuric acid / 3 h / |Reflux 3.1: diisobutylaluminium hydride / toluene; tetrahydrofuran / -10 - 20 °C 4.1: manganese(IV) oxide / ethyl acetate / 20 °C View Scheme

1: diisobutylaluminium hydride / toluene; tetrahydrofuran / -10 - 20 °C 2: manganese(IV) oxide / ethyl acetate / 20 °C View Scheme