1: 77 percent / p-TsOH / benzene / 24 h / Heating; Dean-Stark trap 2: 54 percent / Al2O3 / 1.) 0 deg C, 70 min; 2.) RT; 3.) CH2Cl2, 50 deg C 3: 48 percent / aq. NaOAc, sodium hypophosphite / Raney-nickel / ethanol; acetic acid / 3 h / 50 °C / pH=5.0 4: 90 percent / Amberlyst-15 / acetone; H2O / Heating View Scheme