1: 1. potassium bis(trimethylsilylamide) / 1. THF, toluene, -78 deg C, 30 min; 2. -78 deg C, 45 min 2: sodium periodate / H2O; methanol / 12 h / Ambient temperature 3: toluene / 2 h / Heating 4: 87 percent / 20percent aq. NaOH / dimethylsulfoxide / 3 h / 120 °C 5: oxalyl chloride, DMF / tetrahydrofuran / 2 h / Ambient temperature 6: pyridine / CH2Cl2 / 24 h / Ambient temperature 7: 54 percent / mercuric chloride, mercuric oxide / acetonitrile; H2O / 1 h / Heating 8: 93 percent / tetrahydrofuran / 0.5 h / -10 °C 9: 69 percent / manganese dioxide / CH2Cl2 / 24 h / Ambient temperature 10: 64 percent / N-bromosuccinimide / benzene / 1 h / Irradiation 11: 55 percent / tris(trimethylsilyl)silane, azoisobutyronitrile (AIBN) / toluene / 2 h / 85 °C 12: 36 percent / boron tribromide / CH2Cl2 / 1 h / -40 °C View Scheme

lithium diisopropyl amide in tetrahydrofuran T=-78°C;

potassium hydroxide in ethanol