1: 85 percent / Et3N / benzene / 1 h / Heating 2: 1.) LDA, HMPA, 2.) HMPA / 1.) THF, hexane, 0 deg C, 2.) THF, 1 h, room temperature 3: 1 N sodium ethoxide / ethanol; tetrahydrofuran / 4 h / Ambient temperature 4: water, AcOH / tetrahydrofuran / Ambient temperature View Scheme

1: 85 percent / Et3N / benzene / 1 h / Heating 2: 1.) LDA, HMPA, 2.) HMPA / 1.) THF, hexane, 0 deg C, 2.) THF, 1 h, room temperature View Scheme

lithium diisopropyl amide in tetrahydrofuran; hexane 0.333333 h; Ambient temperature;