1: 87 percent / toluene / Heating 2: 95 percent / HBr; H2O / Heating 3: 98 percent / NaOH; H2O / 12 h / 20 °C View Scheme

1: 97 percent / 35percent aq. H2O2 / methanol / 1 h / Ambient temperature 2: 1.) LDA 2.) Br2 / 1.) THF, -78 deg C, hexane, 15 min 2.) THF, -70 deg C 3: 97 percent / Cu / dimethylformamide / 4 h / 140 °C 4: 50 percent / HSiCl3, NBu3 / xylene / 3 h / 130 °C View Scheme

1: 97 percent / 35percent aq. H2O2 / methanol / 1 h / Ambient temperature 2: 1.) LDA 2.) Br2 / 1.) THF, -78 deg C, hexane, 15 min 2.) THF, -70 deg C 3: 97 percent / Cu / dimethylformamide / 4 h / 140 °C 4: 50 percent / HSiCl3, NBu3 / xylene / 3 h / 130 °C View Scheme

hydrogen iodide; hypophosphorous acid

1.1: H2O2 / methanol / 0.5 h / 20 °C 2.1: LDA / tetrahydrofuran / 1.5 h / -78 °C 2.2: 76 percent / I2 / tetrahydrofuran / 1 h / -78 - 20 °C 3.1: 93 percent / BBr3 / CH2Cl2 / 12 h / 20 °C View Scheme