1: 96 percent / MCPBA / CH2Cl2 / 1 h / Ambient temperature 2: 1.) oxalyl chloride, DMSO, 2.) triethylamine / 1.) CH2Cl2, -60 deg C, 15 min, 2.) CH2Cl2, from -60 deg C to 0 deg C View Scheme

1: 96 percent / MCPBA / CH2Cl2 / 1 h / Ambient temperature 2: 1.) oxalyl chloride, DMSO, 2.) triethylamine / 1.) CH2Cl2, -60 deg C, 15 min, 2.) CH2Cl2, from -60 deg C to 0 deg C 3: 75 percent / ethanol / Ambient temperature View Scheme

1: 89 percent / xylene / Heating 2: 1) ozone, 2) dimethyl sulfide / 1) -60 deg C, 2) room temperature View Scheme

1: 89 percent / xylene / Heating 2: 1) ozone, 2) dimethyl sulfide, water / 1) acetone, -60 deg C, 2) room temperature View Scheme

2: n-BuLi / tetrahydrofuran / -78 °C View Scheme