potassium permanganate; sodium carbonate

1: 54 percent / lithium sulfide / methanol / 4 h 2: 26 percent / triethyl phosphite / 11 h / Irradiation View Scheme

N-bromosuccinmide; dibenzoyl peroxide in dichloromethane 18 h; RefluxIrradiation;

hydrogen bromide in water; toluene T=90°C; 4 h;

phosphorus tribromide 1 h; Heating;

in tetrachloromethane

bromine in tetrachloromethane 2 h; HeatingIrradiation;

1.1: 89 g / p-TsOH / toluene / 2 h / Heating 2.1: n-BuLi / tetrahydrofuran / -25 °C 2.2: 76 percent / tetrahydrofuran / -25 - 20 °C 3.1: 72 percent / TFA; aq. HCl / 0.33 h / 55 °C 4.1: 83 percent / (CH3)2S*BH3 / tetrahydrofuran / 0.25 h / 0 °C 5.1: 63 percent / PBr3 / 1 h / Heating View Scheme

1.1: n-BuLi / tetrahydrofuran / 1 h / -50 °C 1.2: tetrahydrofuran / -50 - 20 °C 2.1: 89 g / p-TsOH / toluene / 2 h / Heating 3.1: n-BuLi / tetrahydrofuran / -25 °C 3.2: 76 percent / tetrahydrofuran / -25 - 20 °C 4.1: 72 percent / TFA; aq. HCl / 0.33 h / 55 °C 5.1: 83 percent / (CH3)2S*BH3 / tetrahydrofuran / 0.25 h / 0 °C 6.1: 63 percent / PBr3 / 1 h / Heating View Scheme

1: 83 percent / (CH3)2S*BH3 / tetrahydrofuran / 0.25 h / 0 °C 2: 63 percent / PBr3 / 1 h / Heating View Scheme