1: 100 percent / MCPBA / CH2Cl2 / 1 h / Ambient temperature 2: 91 percent / 5percent sodium amalgam / ethanol / 12 h / Heating 3: BF3*CH3COOH / CH2Cl2 / 2 h / Ambient temperature 4: MCPBA, KF / dimethylformamide / 40 h / Ambient temperature View Scheme

With  3-chloro-benzenecarboperoxoic acid in  dichloromethane 1 h;  Ambient temperature;