1: With acetic anhydride in acetic acid T=200°C; 1 h; 2: With dihydrogen peroxide; (NH4)3PMo12O40*6H2O in dichloromethane; water 2 h; Heating / reflux; 3: With potassium carbonate in dichloromethane; water 2 h; Heating / reflux; Product distribution / selectivity;