1: 1.) n-BuLi / 1.) THF, hexane -50 deg C, 20 min, 2.) from -78 deg C to 0 deg C 2: chromic acid / acetone / 1 h / 0 - 5 °C 3: 100 percent / K2CO3 / tetrahydrofuran / 3 h / Heating View Scheme