1: O3 / CH2Cl2 / -78 °C 2: imidazol / dimethylformamide / Ambient temperature 3: 62 percent / 1.62 M BuLi / hexane; tetrahydrofuran / 1.) 30 min; 2.) 3 h, -78 deg C 4: 1.) 1.9 M Me3Al / 1.) hexane, CH2Cl2, 20 min; 1 h; 2.) hexane, THF, CH2Cl2, -50 deg C 5: 91 percent / 90 percent m-chloroperbenzoic acid / CH2Cl2 / 1 h 6: 85 percent / DCC / 4-(dimethylamino)pyridine / CH2Cl2 / 24 h 7: 100 percent / 50 percent aq. CF3COOH / 2 h / Ambient temperature View Scheme