1: 80 percent / lithium diisopropyl amide / hexane; tetrahydrofuran; hexamethylphosphoric acid triamide / 1.) -78 deg C, 1 hr., 2.) r.t., 2 hrs. 2: 40 percent / actic acid / 4 h / Heating View Scheme

1: 1.) n-BuLi / 1.) THF, hexane, 0 deg C, 40 min, 2.) THF, hexane, RT 2: Amberlyst-15, H2O / acetone View Scheme

1: 1.) n-BuLi / 1.) THF, hexane, 0 deg C, 40 min, 2.) THF, hexane, RT 2: Amberlyst-15, H2O / acetone 3: 47 percent / p-benzoquinone, PdCl2, H2O / dimethylformamide / 3 h / 70 °C View Scheme

1: 1) n-BuLi / 1) THF, HMPA, hexane, -78 deg C, 45 min, 2) THF, -78 deg C to room temperature, overnight 2: 52 percent / Cu(OAc)2*H2O / tetrahydrofuran; H2O / 0.67 h 3: 1) sodium hydride / 1) DMSO, room temperature, 15 min, 2) DMSO, 60 deg C, 3 h 4: p-toluenesulphonic acid / acetone / 5 h View Scheme

1: 1) n-BuLi / 1) THF, HMPA, hexane, -78 deg C, 45 min, 2) THF, -78 deg C to room temperature, overnight 2: 52 percent / Cu(OAc)2*H2O / tetrahydrofuran; H2O / 0.67 h View Scheme

1: 1.) n-BuLi / 1.) THF, hexane, 0 deg C, 40 min, 2.) THF, hexane, RT 2: Amberlyst-15, H2O / acetone 3: 1.) O3, 2.) Zn, AcOH / 1.) MeOH, CH2Cl2, -78 deg C, 2.) MeOH, CH2Cl2, RT, 3 h View Scheme