1: sodium hydrogencarbonate; 3-chloro-benzenecarboperoxoic acid / dichloromethane / 0 - 25 °C 2: water; hydrogen bromide / chloroform / 0.5 h / 20 °C 3: pyridinium chlorochromate / dichloromethane / 13 h / 20 °C View Scheme

1: water; hydrogen bromide / chloroform / 0.5 h / 20 °C 2: pyridinium chlorochromate / dichloromethane / 13 h / 20 °C View Scheme

1.1: iodine; magnesium / tetrahydrofuran / 0.5 h / 10 - 15 °C 1.2: 16 h / 0 - 25 °C 2.1: toluene-4-sulfonic acid / benzene / 3 h / Reflux 3.1: sodium hydrogencarbonate; 3-chloro-benzenecarboperoxoic acid / dichloromethane / 0 - 25 °C 4.1: water; hydrogen bromide / chloroform / 0.5 h / 20 °C 5.1: pyridinium chlorochromate / dichloromethane / 13 h / 20 °C View Scheme

sodium azide in dimethyl sulfoxide T=25°C; 5 h;

1.1: sodium azide / dimethyl sulfoxide / 5 h / 25 °C 2.1: triphenylphosphine / tetrahydrofuran / 12 h / 65 °C 2.2: 3 h / Reflux 3.1: hydrogen bromide; bromine / water / 70 °C 4.1: DBN / acetonitrile / 25 h / Reflux View Scheme