triethylamine in benzene T=40°C; 2 h;

1: peroxyacetic acid / CH2Cl2 / 12 h / Ambient temperature 2: 1.) 10percent ethanolic H2SO4 2.) 20percent ethanolic KOH / 1.) room temperature, 24h 2.) room temperature, 24h 3: 89 percent / Et3N / benzene / 2 h / 40 °C View Scheme