hydrogen bromide T=45°C; 12 h;

Multi-step reaction with 4 steps 1: 1.) t-BuLi / 1.) hexane, THF, -80 deg C, 1h 2.) -40 deg C, 4h2: 72 percent / m-chloroperbenzoic acid / CH2Cl2 / 1 h / Ambient temperature3: 91 percent / methanol / 0.5 h / -30 °C4: 1.) LDA 2.) oxodiperoxymolybdenum(pyridine)(hexamethylphosphoric triamide) / 1.) THF, -90 deg C, 1h 2.) -80 deg C, 2h