1: 49 percent / 30percent H2O2aq., AcOH / tetrahydrofuran / 1 h / -2 - 0 °C 2: 89 percent / Et3N / CHCl3 / 1 h / Ambient temperature 3: 82 percent / AlCl3, anisole / 0.17 h / 0 °C 4: 81 percent / aq HCl / methanol / 4 h / Heating 5: 84 percent / Fremy's salt, KH2PO4 / H2O; acetone / 0.17 h / Ambient temperature View Scheme