1: 70 percent 2: n-BuLi / 1.) THF, ether, -90 deg C, 0.5 h; 2.) -75 deg C 3: 79 percent / N(Et)3, 2,4-Dinitrobenzenesulfenyl chloride / CH2Cl2 / 0.75 h / Heating 4: m-Chloroperbenzoic acid (85percent) / CCl4 / 0.17 h / 20 - 30 °C 5: NBS, Dibenzoyl peroxide / CCl4 / 7 h / Heating 6: Benzyltriethylammonium chloride / acetonitrile / 22 h / 30 °C 7: 1,5-Diazabicyclo<5.4.0>undec-5-ene / benzene-d6 / 0.67 h 8: p-TsOH / CH2Cl2 / 0.5 h View Scheme

1: n-BuLi / 1.) THF, ether, -90 deg C, 0.5 h; 2.) -75 deg C 2: 79 percent / N(Et)3, 2,4-Dinitrobenzenesulfenyl chloride / CH2Cl2 / 0.75 h / Heating 3: m-Chloroperbenzoic acid (85percent) / CCl4 / 0.17 h / 20 - 30 °C 4: NBS, Dibenzoyl peroxide / CCl4 / 7 h / Heating 5: Benzyltriethylammonium chloride / acetonitrile / 22 h / 30 °C 6: 1,5-Diazabicyclo<5.4.0>undec-5-ene / benzene-d6 / 0.67 h 7: p-TsOH / CH2Cl2 / 0.5 h View Scheme

1: m-Chloroperbenzoic acid (85percent) / CCl4 / 0.17 h / 20 - 30 °C 2: NBS, Dibenzoyl peroxide / CCl4 / 7 h / Heating 3: Benzyltriethylammonium chloride / acetonitrile / 22 h / 30 °C 4: 1,5-Diazabicyclo<5.4.0>undec-5-ene / benzene-d6 / 0.67 h 5: p-TsOH / CH2Cl2 / 0.5 h View Scheme

1: 79 percent / N(Et)3, 2,4-Dinitrobenzenesulfenyl chloride / CH2Cl2 / 0.75 h / Heating 2: m-Chloroperbenzoic acid (85percent) / CCl4 / 0.17 h / 20 - 30 °C 3: NBS, Dibenzoyl peroxide / CCl4 / 7 h / Heating 4: Benzyltriethylammonium chloride / acetonitrile / 22 h / 30 °C 5: 1,5-Diazabicyclo<5.4.0>undec-5-ene / benzene-d6 / 0.67 h 6: 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: 1,5-Diazabicyclo<5.4.0>undec-5-ene / benzene-d6 / 0.67 h 4: p-TsOH / CH2Cl2 / 0.5 h View Scheme

toluene-4-sulfonic acid in dichloromethane 0.5 h;

1: 1,5-Diazabicyclo<5.4.0>undec-5-ene / benzene-d6 / 0.67 h 2: p-TsOH / CH2Cl2 / 0.5 h View Scheme

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