1: NBS, Dibenzoyl peroxide / CCl4 / 7 h / Heating 2: Benzyltriethylammonium chloride / acetonitrile / 22 h / 30 °C 3: 1,5-Diazabicyclo<5.4.0>undec-5-ene / benzene-d6 / 0.67 h 4: p-TsOH / CH2Cl2 / 0.5 h View Scheme

1: NBS, Dibenzoyl peroxide / CCl4 / 7 h / Heating 2: Benzyltriethylammonium chloride / acetonitrile / 22 h / 30 °C 3: 1.) t-BuOCl; 2.) DBU / 1.) CCl4, 4 h, reflux, irradiation; 2.) CH2Cl2, 30 deg C, 2 h View Scheme

1: NBS, Dibenzoyl peroxide / CCl4 / 7 h / Heating 2: Benzyltriethylammonium chloride / acetonitrile / 22 h / 30 °C 3: 1.) t-BuOCl; 2.) DBU / 1.) CCl4, 4 h, reflux, irradiation; 2.) CH2Cl2, 30 deg C, 2 h 4: p-TsOH / CH2Cl2 / 0.5 h / 35 °C View Scheme

1: NBS, Dibenzoyl peroxide / CCl4 / 7 h / Heating 2: Benzyltriethylammonium chloride / acetonitrile / 22 h / 30 °C 3: 1.) t-BuOCl; 2.) DBU / 1.) CCl4, 4 h, reflux, irradiation; 2.) CH2Cl2, 30 deg C, 2 h 4: p-TsOH / CH2Cl2 / 0.5 h / 35 °C View Scheme