sodium tetrahydroborate in methanol T=0°C; 1.8 h;

zinc in acetic acid T=60 - 70°C; 6 h;

1: 1) NBS, AIBN; 2) DBU / 1) CCl4, reflux, 1.25 h; 2) CH2Cl2, reflux, 1 h 2: 1) AgNO3, Br2; 2) DBU / 1) room temp., 8.5 h; 2) CH2Cl2, reflux, 2.33 h 3: 53 percent / tetrahydrofuran / 0.5 h / 0 °C 4: 1) 95percent aq. H2SO4, 2) CF3SO3H / 1) room temp., 40 min; 2) 1 h at room temp., then 2.5 h at 45-55 deg C, then 2.66 h at 60-70 deg C 5: 98 percent / Et3N / toluene / 0.42 h / 80 °C 6: 67 percent / 13percent aq. KOH / ethanol / 25 h / Heating 7: 89 percent / NaBH4 / methanol / 1.8 h / 0 °C View Scheme

1: 1) AgNO3, Br2; 2) DBU / 1) room temp., 8.5 h; 2) CH2Cl2, reflux, 2.33 h 2: 53 percent / tetrahydrofuran / 0.5 h / 0 °C 3: 1) 95percent aq. H2SO4, 2) CF3SO3H / 1) room temp., 40 min; 2) 1 h at room temp., then 2.5 h at 45-55 deg C, then 2.66 h at 60-70 deg C 4: 98 percent / Et3N / toluene / 0.42 h / 80 °C 5: 67 percent / 13percent aq. KOH / ethanol / 25 h / Heating 6: 89 percent / NaBH4 / methanol / 1.8 h / 0 °C View Scheme

1: 53 percent / tetrahydrofuran / 0.5 h / 0 °C 2: 1) 95percent aq. H2SO4, 2) CF3SO3H / 1) room temp., 40 min; 2) 1 h at room temp., then 2.5 h at 45-55 deg C, then 2.66 h at 60-70 deg C 3: 98 percent / Et3N / toluene / 0.42 h / 80 °C 4: 67 percent / 13percent aq. KOH / ethanol / 25 h / Heating 5: 89 percent / NaBH4 / methanol / 1.8 h / 0 °C View Scheme

1: 1) 95percent aq. H2SO4, 2) CF3SO3H / 1) room temp., 40 min; 2) 1 h at room temp., then 2.5 h at 45-55 deg C, then 2.66 h at 60-70 deg C 2: 98 percent / Et3N / toluene / 0.42 h / 80 °C 3: 67 percent / 13percent aq. KOH / ethanol / 25 h / Heating 4: 89 percent / NaBH4 / methanol / 1.8 h / 0 °C View Scheme

1: 98 percent / Et3N / toluene / 0.42 h / 80 °C 2: 67 percent / 13percent aq. KOH / ethanol / 25 h / Heating 3: 89 percent / NaBH4 / methanol / 1.8 h / 0 °C View Scheme

1: 58 percent / CF3SO3H / 3 h / 45 °C 2: 98 percent / Et3N / toluene / 0.42 h / 80 °C 3: 67 percent / 13percent aq. KOH / ethanol / 25 h / Heating 4: 89 percent / NaBH4 / methanol / 1.8 h / 0 °C View Scheme

1: 67 percent / 13percent aq. KOH / ethanol / 25 h / Heating 2: 89 percent / NaBH4 / methanol / 1.8 h / 0 °C View Scheme

1: 83 percent / NaBH4 / methanol / 1 h / 0 °C 2: 69 percent / Zn dust / acetic acid / 6 h / 60 - 70 °C View Scheme