1: 87 percent / N-bromosuccinimide, Me2S / CH2Cl2 / 5 h 2: 92 percent / m-chloroperbenzoic acid / CH2Cl2 / 12 h / 0 °C View Scheme

N-bromosuccinmide; dimethylsulfide in dichloromethane 5 h;

N-chloro-succinimide; dimethylsulfide in dichloromethane T=20°C; Inert atmosphere;

Multi-step reaction with 2 steps 1: 94 percent / toluene-p-sulfonic acid / toluene / Heating2: 91 percent / diisobutylaluminium hydride / diethyl ether; hexane / 1) -40 deg C to room temperature, 2) room temperature, 12 h