1: 1.) LDA / 1.) THF, -78 deg C, 2 h; room temperature, 1 h, 2.) -78 deg C, 1 h 2: 72 percent / tetrahydrofuran / 1 h / 0 °C 3: 80 percent / MnO2, pyridine / CH2Cl2 / 0.5 h / Heating 4: 72 percent / BF3*OEt / tetrahydrofuran / 0.5 h / 50 °C 5: 61 percent / toluene / 20 h / Heating 6: 95 percent / TFA / toluene / 0.5 h / Heating 7: 68 percent / DDQ / benzene / 5 h / Heating 8: 87 percent / aq. NaOH / methanol; tetrahydrofuran / 3 h / Heating View Scheme

sodium tetrahydroborate in tetrahydrofuran; ethanol T=0 - 5°C; 1.25 h;

1: 1) n-Bu4NHSO4, NaOH / 1) CH2Cl2, 0 deg C, 2) CH2Cl2, 0 - 5 deg C, 25 min 2: 100 percent / NaBH4 / tetrahydrofuran; aq. ethanol / 1.25 h / 0 - 5 °C View Scheme

1: 86 percent / LDA / tetrahydrofuran / -70 °C 2: sodium borohydride / tetrahydrofuran; H2O / 0 - 5 °C View Scheme

ethylmagnesium bromide in tetrahydrofuran 1.) 0 deg C, 30 min, r.t., 30 min; 2.) r.t., overnight;

potassium hydroxide in ethanol 2 h; Ambient temperature; Yield given;

1: tert-butyllithium / tetrahydrofuran / -40 - 23 °C 2: tetrahydrofuran / -70 °C View Scheme

lithium diisopropyl amide 1) THF, hexane, a) -75 deg C, 90 min, b) rt, 30 min, 2) -65 to -40 deg C, overnight; Yield given. Multistep reaction;

1: 1) lithium diisopropylamide / 1) THF, hexane, a) -75 deg C, 90 min, b) rt, 30 min, 2) -65 to -40 deg C, overnight 2: 46 percent / KF, hydroquinone, AcOH / 3 h / 100 - 105 °C View Scheme