1: 1.) CH3COOH, 2.) CH3SO2Cl / 1.) EtOH, water, reflux, 1,5 h, 2.) pyridine, 0 deg C, 30 min; room temp, 1 h 2: 87 percent / Pb(OAc)4 / cyclohexane / 1 h / Ambient temperature 3: 88 percent / Al2O3 / benzene / Ambient temperature View Scheme