1: 90 percent / BBr3 / CH2Cl2 / 0.5 h / 0 °C 2: 97 percent / K2CO3 / acetone / 2 h / Heating 3: 86 percent / dimethyl dioxirane / acetone; CH2Cl2 / 0.5 h / 0 - 20 °C View Scheme

1: 90 percent / BBr3 / CH2Cl2 / 0.5 h / 0 °C 2: 65 percent / dimethyl dioxirane / acetone; CH2Cl2 / 1 h / 0 - 20 °C 3: 95 percent / K2CO3 / acetone / 6 h / Heating 4: 71 percent / I2; pyridine / 8 h / Heating 5: 94 percent / BBr3 / CH2Cl2 / 0.5 h / 0 °C View Scheme

1: 90 percent / BBr3 / CH2Cl2 / 0.5 h / 0 °C View Scheme

1: 90 percent / BBr3 / CH2Cl2 / 0.5 h / 0 °C 2: 97 percent / K2CO3 / acetone / 2 h / Heating 3: 86 percent / dimethyl dioxirane / acetone; CH2Cl2 / 0.5 h / 0 - 20 °C 4: 96 percent / K2CO3 / acetone / 1 h / Heating 5: 99 percent / BBr3 / CH2Cl2 / 0.5 h / 0 °C 6: 89 percent / dimethyl dioxirane / acetone; CH2Cl2 / 0.83 h / 0 - 20 °C View Scheme