1: 93 percent / CH2Cl2 / 1 h / Ambient temperature 2: KOH / 1) MeOH, H2O, heating, 15 min, 2) MeOH, H2O, air stream, 10 min 3: conc. HCl / CH2Cl2; diethyl ether / 0.17 h / 20 °C 4: 0.33 h / 150 °C 5: 1 N NaOH, Na2S2O4 / methanol / 0.17 h / Heating 6: conc. H2SO4, H2O / 10 h / 100 °C View Scheme