1: 87 percent / formic acid / 18 h / Ambient temperature 2: 86 percent / ozone / CH2Cl2 / -78 °C 3: 83 percent / ethanol / 0.5 h / Ambient temperature 4: 78 percent / TMEDA, n-butyllithium / tetrahydrofuran; hexane / from -78 to room temperature, 17 h 5: 82 percent / triethylamine, 4-(dimethylamino)pyridine / CH2Cl2 / 2.5 h / Ambient temperature 6: 79 percent / m-chloroperbenzoic acid / CH2Cl2 / 1.25 h / -78 °C 7: 53 percent / lithiumhydroxyde / tetrahydrofuran; H2O / 24 h / 50 °C View Scheme

Multi-step reaction with 2 steps 1: 87 percent / formic acid / 18 h / Ambient temperature2: 86 percent / ozone / CH2Cl2 / -78 °C  

Multi-step reaction with 4 steps 1: 87 percent / formic acid / 18 h / Ambient temperature2: 86 percent / ozone / CH2Cl2 / -78 °C3: 83 percent / ethanol / 0.5 h / Ambient temperature4: 78 percent / TMEDA, n-butyllithium / tetrahydrofuran; hexane / from -78 to room temperature, 17 h  

Multi-step reaction with 2 steps 1: potassium iodide / dimethylformamide / 17 h / 80 °C2: 1.) LDA / 1.) hexane, THF, -78 deg C, 30 min; 2.) THF, -20 deg C, 5 h  

Multi-step reaction with 5 steps 1: 87 percent / formic acid / 18 h / Ambient temperature2: 86 percent / ozone / CH2Cl2 / -78 °C3: 83 percent / ethanol / 0.5 h / Ambient temperature4: 78 percent / TMEDA, n-butyllithium / tetrahydrofuran; hexane / from -78 to room temperature, 17 h5: 82 percent / triethylamine, 4-(dimethylamino)pyridine / CH2Cl2 / 2.5 h / Ambient temperature