1: 88 percent / DMAP, NEt3 / CH2Cl2 / 0 °C 2: POCl3 / benzene / Heating 3: NaBH4 / methanol / 4 h / -78 °C 4: 82 percent / H2 / Pd/C / ethanol; aq. HCl View Scheme

1.1: dicyclohexyl-carbodiimide; 4-(N,N-dimethlyamino)pyridine / dichloromethane / 2 h / 20 °C 2.1: trichlorophosphate / benzene / 7 h / |Reflux 2.2: 3 h / 20 °C / |Inert atmosphere 3.1: boron tribromide / dichloromethane / 2 h / -78 - 20 °C View Scheme

1.1: (benzotriazo-1-yloxy)tris(dimethylamino)phosphonium hexafluorophosphate; triethylamine / acetonitrile / 15 h / 20 °C 2.1: trichlorophosphate / toluene / 16 h / |Reflux 2.2: 3 h / -78 °C 3.1: palladium; hydrogen; hydrogenchloride / ethyl acetate; water; ethanol / 18 h 4.1: sodium cyanoborohydride / acetic acid / 24 h / 20 °C View Scheme

1.1: (benzotriazo-1-yloxy)tris(dimethylamino)phosphonium hexafluorophosphate; triethylamine / acetonitrile / 15 h / 20 °C 2.1: trichlorophosphate / toluene / 16 h / |Reflux 2.2: 3 h / -78 °C 3.1: palladium; hydrogen; hydrogenchloride / ethyl acetate; water; ethanol / 18 h View Scheme

Stage #1: With  boron trifluoride diethyl etherate; complex boron hydride with tetrahydrofurane in  tetrahydrofuran 2 h;  Inert atmosphereReflux; Stage #2: With  hydrogenchloride in  tetrahydrofuran; water T=0°C; 12 h;   

Multi-step reaction with 2 steps 1: 88 percent / DMAP, NEt3 / CH2Cl2 / 0 °C2: POCl3 / benzene / Heating  

Multi-step reaction with 3 steps 1: 88 percent / DMAP, NEt3 / CH2Cl2 / 0 °C2: POCl3 / benzene / Heating3: NaBH4 / methanol / 4 h / -78 °C