1: 1.) hydrogen chloride, 2.) Raney nickel / 1.) ethanol, RT, 21 h, 2.) ethanol, reflux, 4 h 2: 1.) ozone, 2.) dimethyl sulfide / 1.) CH2Cl2, -70 deg C, 10 min, 2.) CH2Cl2, RT, 1 h 3: 0.1 N sodium methoxide / ethanol / 0.5 h / 0 °C 4: NaBH4 / ethanol / 0.5 h / Ambient temperature 5: 70.7 percent / potassium carbonate / dimethylformamide / 0.5 h / Ambient temperature View Scheme