1: 83 percent / conc. hydrochloric acid / 2 h 2: 46 percent / 3-chloroperbenzoic acid / CH2Cl2 / 12 h / Ambient temperature 3: 1.) diphenylphosphine, butyllithium, 2.) methyl iodide / CH2Cl2 / 12 h / Ambient temperature; 1.) THF, hexane, room temp., 7 h, 2.) 30 min 4: 90 percent / acetic acid / 6 h / 40 °C View Scheme