1: 1.) n-BuLi, 2.) HMPA / 1.) THF, hexane, -78 deg C, 15 min, 2a.) THF, hexane, -78 deg C, 40 min, 2b.) -20 deg C, 30 min 2: 48 percent / tetra-n-butylammonium fluoride / tetrahydrofuran / 5 h / 25 °C 3: 68 percent / K2CO3 / methanol; H2O / 12 h / Ambient temperature View Scheme