boron tribromide in dichloromethane 1.) -78 deg C, 60 min, 2.) room temp., 90 min;

in ethyl acetate

1: diisobutylaluminium hydride / tetrahydrofuran; toluene / 3 h / -78 °C 2: 84 percent / triethylamine, 4-dimethylaminopyridine / dimethylformamide / 25 h / from 0 deg C to room temperature 3: 87 percent / 50percent aq. HF / acetonitrile; CH2Cl2 / 1.8 h / Ambient temperature 4: 97 percent / oxalyl chloride, dimethylsulfoxide / CH2Cl2 / 0.75 h / -60 - -10 °C 5: p-toluenesulfonic acid / benzene / 47 h / Heating 6: 1M tetrabutylammonium fluoride, acetic acid / tetrahydrofuran / 0.25 h / 0 °C View Scheme

1: 76 percent / t-BuOK / tetrahydrofuran / 0.75 h / -20 °C 2: 3 percent / NaBH4 / dimethylformamide / 0.5 h / 60 °C 3: 84 percent / BBr3 / CH2Cl2 / 1.) -78 deg C, 60 min, 2.) room temp., 90 min View Scheme

tetrabutyl ammonium fluoride; acetic acid in tetrahydrofuran T=0°C; 0.25 h; Yield given;

tetrabutyl ammonium fluoride; acetic acid in tetrahydrofuran T=0°C; 0.25 h; Yield given;

1: 100 percent / DMAP / tetrahydrofuran / 6 h / Heating 2: 76 percent / LAH / tetrahydrofuran; diethyl ether / 24 h / Heating 3: 91 percent / tetrahydrofuran / -15 - 20 °C 4: 100 percent / aq. sodium metaperiodate / methanol / 24 h / Ambient temperature 5: 94 percent / Na2CO3 / toluene / 6 h / Heating 6: 79 percent / BBr3 / CH2Cl2 / 3.5 h / -78 - 20 °C View Scheme

1: 80 percent / NaOH / H2O 2: (COCl)2 / CH2Cl2 3: NaN3 / H2O; acetone 4: toluene / 100 °C 5: Li(t-BuO)3AlH / tetrahydrofuran 6: 70 percent / NaHCO3 / methanol; H2O View Scheme

1: Li(t-BuO)3AlH / tetrahydrofuran 2: 70 percent / NaHCO3 / methanol; H2O View Scheme

1: 56 percent / toluene-p-sulfonic acid / 1,2-dimethoxy-ethane / 30 h / Heating 2: 67 percent / BBr3 / CH2Cl2 / 1.) -78 deg C, 1 h, 2.) -78 deg C to room temperature, 1 h, 3.) room temperature, 1.5 h View Scheme