1: aq. NaOH 2: t-BuOK / tetrahydrofuran; hexamethylphosphoric acid triamide / Ambient temperature 3: 1.) n-BuLi, diisopropylamine / 1.) hexane, THF, HMPA, -60 deg C, 2.) hexane, THF, HMPA, -60 deg C, 1 h View Scheme

1: ethanol / Heating 2: aq. NaOH / 70 °C 3: aq. NaOH 4: t-BuOK / tetrahydrofuran; hexamethylphosphoric acid triamide / Ambient temperature 5: 1.) n-BuLi, diisopropylamine / 1.) hexane, THF, HMPA, -60 deg C, 2.) hexane, THF, HMPA, -60 deg C, 1 h View Scheme

1: aq. NaOH / 70 °C 2: aq. NaOH 3: t-BuOK / tetrahydrofuran; hexamethylphosphoric acid triamide / Ambient temperature 4: 1.) n-BuLi, diisopropylamine / 1.) hexane, THF, HMPA, -60 deg C, 2.) hexane, THF, HMPA, -60 deg C, 1 h View Scheme

n-butyllithium; diisopropylamine 1.) hexane, THF, HMPA, -60 deg C, 2.) hexane, THF, HMPA, -60 deg C, 1 h; Yield given. Multistep reaction;