1: aq. 48percent HBr / acetic acid / 0.5 h / 85 °C 2: 59 percent / H2 / W-2 Raney Nickel / ethanol; tetrahydrofuran / 6 h 3: 1.) t-butyllithium / 1.) toluene, ether, pentan, -100 deg C, 20 min. 2.) 0 deg C; 4: 64 percent / m-chloroperoxybenzoic acid / CH2Cl2 / 1.) -30 to -20 deg C, 10 min, 2.) heating from -30 to -5 deg C, 2 h; View Scheme

1: aq. 48percent HBr / acetic acid / 0.5 h / 85 °C 2: 59 percent / H2 / W-2 Raney Nickel / ethanol; tetrahydrofuran / 6 h 3: 1.) t-butyllithium / 1.) toluene, ether, pentan, -100 deg C, 20 min. 2.) 0 deg C; View Scheme

1: aq. 48percent HBr / acetic acid / 0.5 h / 85 °C 2: 59 percent / H2 / W-2 Raney Nickel / ethanol; tetrahydrofuran / 6 h 3: 1.) t-butyllithium, / 1.) toluene, ether, pentan, -100 deg C, 20 min. 2.) -95 deg C; View Scheme

hydrogen bromide in acetic acid T=85°C; 0.5 h; Yield given;

1: aq. 48percent HBr / acetic acid / 0.5 h / 85 °C 2: 59 percent / H2 / W-2 Raney Nickel / ethanol; tetrahydrofuran / 6 h View Scheme

1: aq. 48percent HBr / acetic acid / 0.5 h / 85 °C 2: 80 percent / 1,8-diazabicyclo<5.4.0>undec-7-ene / tetrahydrofuran / 1 h / 25 °C View Scheme

1: aq. 48percent HBr / acetic acid / 0.5 h / 85 °C 2: 59 percent / H2 / W-2 Raney Nickel / ethanol; tetrahydrofuran / 6 h 3: 1.) t-butyllithium, 2.) methanol / 1.) toluene, ether, pentan, -100 deg C, 20 min. 2.) -85 deg C; View Scheme

1: aq. 48percent HBr / acetic acid / 0.5 h / 85 °C 2: 59 percent / H2 / W-2 Raney Nickel / ethanol; tetrahydrofuran / 6 h 3: 1.) t-butyllithium / 1.) toluene, ether, pentan, -100 deg C, 20 min. 2.) 0 deg C; 4: 73 percent / potassium persulfate / methanol; tetrahydrofuran; H2O / 3 h / 30 °C View Scheme