1: N-chlorosuccinimide / CCl4 / 10 h / Ambient temperature 2: 89 percent / anhydrous ZnBr2 / CH2Cl2 / 2 h / Ambient temperature 3: 1.) m-chloroperbenzoic acid / 1.) CH2Cl2, 0 degC, 30 min., 2.) toluene, 100 degC, 4h 4: 62 percent / 6N hydrochloric acid / methanol / 8 h / Heating View Scheme