lithium aluminium tetrahydride in diethyl ether 1 h; Heating;

lithium aluminium tetrahydride in tetrahydrofuran T=-10°C; Inert atmosphereReflux;

phosphorus tribromide

1: 95 percent / PBr3 / diethyl ether / 2 h 2: 1.) CuI / 1.) THF, -40 deg C, 10 min, 2.) THF, -25 deg C, 2.5 h 3: 1.) Hg(OAc)2, 2.) NaBH4 / 1.) THF, H2O, 20 min, 2.) THF, H2O, 20 min 4: 1.) NaH / 1.) THF, RT, 45 min 5: tetrahydrofuran / 2 h / 65 °C 6: 1.) ethanethiol, NaH / 1.) DMF, RT, 1 h, 2.) DMF, 130 deg C, 6 h 7: 1.) NaH, 2.) NaI / 1.) HMPA, 30 min, 2.) HMPA, RT, 2 h 8: 80 percent / ethanethiol, NaH / dimethylformamide / 18 h / 120 °C 9: 92 percent / W-6 Raney nickel / ethanol / 3 h / Heating View Scheme