1: 13.8 percent / KMnO4, 18-crown-6 / benzene / 3 h / 17 °C 2: 98.6 percent / 30percent aq. KOH / ethanol / 30 h / 55 - 60 °C 3: 58.6 percent / 40percent NaOH / methanol / 2 h / Heating View Scheme

Multi-step reaction with 2 steps 1: 73.5 percent / P2O5 / xylene / 3.5 h / 140 °C2: 76.3 percent / pyridine / 3.5 h / 13 °C  

With  potassium permanganate; 18-crown-6 ether in  benzene T=17°C; 3 h;