1: 77 percent / DDQ / acetone; H2O / 1.) -78 deg C, 2.) from -78 deg C to room temp., 45 min 2: 78 percent / 1 N aq. NaOH / 16.5 h / 70 °C 3: 85 percent / sulfur / xylene / 17 h / Heating 4: 63 percent / methanol; diethyl ether / -78 - 20 °C View Scheme