1: CH2Cl2 / 1 h / -78 °C / Irradiation 2: potassium carbonate / ethane-1,2-diol / 4 h / 120 °C 3: 1.) N-bromosuccinimide (NBS), AIBN, 2.) NaI / 1.) carbon tetrachloride, 12 h, reflux, 2.) acetone, 2 h, reflux 4: 1.) O3, 2.)trifluoroacetic acid / 1.) CH2Cl2, -78 deg C, 2.) CH2Cl2, -78 deg C, 3 h View Scheme

1: CH2Cl2 / 1 h / -78 °C / Irradiation 2: potassium carbonate / ethane-1,2-diol / 4 h / 120 °C View Scheme

in dichloromethane T=-78°C; 1 h; Irradiation; Yield given. Yields of byproduct given;

1: CH2Cl2 / 1 h / -78 °C / Irradiation 2: potassium carbonate / ethane-1,2-diol / 4 h / 120 °C 3: 1.) N-bromosuccinimide (NBS), AIBN, 2.) NaI / 1.) carbon tetrachloride, 12 h, reflux, 2.) acetone, 2 h, reflux View Scheme

in dichloromethane T=-78°C; 1 h; Irradiation; Yield given. Yields of byproduct given;

1: CH2Cl2 / 1 h / -78 °C / Irradiation 2: potassium carbonate / ethane-1,2-diol / 4 h / 120 °C 3: 85 percent / aluminum chloride / CH2Cl2 / 1 h / 0 °C 4: 1.) N-bromosuccinimide (NBS), AIBN, 2.) NaI / 1.) carbon tetrachloride, 12 h, reflux, 2.) acetone, 2 h, reflux 5: 92 percent / O3 / methanol / -78 - 20 °C View Scheme

in dichloromethane T=-78°C; 1 h; Irradiation; Yield given. Yields of byproduct given;

Multi-step reaction with 4 steps 1: CH2Cl2 / 1 h / -78 °C / Irradiation2: potassium carbonate / ethane-1,2-diol / 4 h / 120 °C3: 85 percent / aluminum chloride / CH2Cl2 / 1 h / 0 °C4: 1.) N-bromosuccinimide (NBS), AIBN, 2.) NaI / 1.) carbon tetrachloride, 12 h, reflux, 2.) acetone, 2 h, reflux  

Multi-step reaction with 7 steps 1: CH2Cl2 / 1 h / -78 °C / Irradiation2: potassium carbonate / ethane-1,2-diol / 4 h / 120 °C3: 1.) N-bromosuccinimide (NBS), AIBN, 2.) NaI / 1.) carbon tetrachloride, 12 h, reflux, 2.) acetone, 2 h, reflux4: 69 percent / Na / ethanol / 5 h / Heating5: thionyl chloride / pyridine / 5 h / Ambient temperature6: p-toluenesulfonic acid / benzene / 1 h / Heating7: O3 / methanol / -78 - 20 °C