1.1: 74 percent / sodium iodide / acetone / Heating 2.1: naphthalene; sodium / tetrahydrofuran / 20 °C 2.2: 45 percent / tetrahydrofuran / 20 h / Heating 3.1: m-chloroperbenzoic acid / CH2Cl2 / 0.5 h / cooling 3.2: CDCl3 View Scheme

Multi-step reaction with 4 steps 1: hexamethylphosphoric acid triamide; acetone / 192 h / 65 - 70 °C2: 63 percent / 5 percent K2CO3 / ethanol; H2O3: manganese dioxide / petroleum ether / 1.5 h4: 73.9 percent / p-TsOH / tetrahydrofuran; ethanol / 30 h / 40 °C