1: 64 percent / pyridine / 20 h / Ambient temperature 2: 90 percent / conc. HCl / CHCl3; methanol / 64 h / Ambient temperature 3: 89 percent / aluminium isopropoxide / toluene; cyclohexanone / 0.75 h / Heating 4: 80 percent / 5percent KOH / methanol / 4 h / 65 °C View Scheme