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  

Multi-step reaction with 7 steps 1: 51 percent / 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