Multi-step reaction with 2 steps 1: 70 percent / BH3*THF / tetrahydrofuran / 1 h / -78 °C2: 89 percent / NaBH4 / methanol / 18 h / Ambient temperature  

Multi-step reaction with 5 steps 1: 95 percent / NaH / tetrahydrofuran / 4 h / Heating2: 63 percent / titanium tetra-iso-propoxide / Heating3: 96 percent / K2CO3 / dimethylformamide / 16 h / Ambient temperature4: 70 percent / BH3*THF / tetrahydrofuran / 1 h / -78 °C5: 89 percent / NaBH4 / methanol / 18 h / Ambient temperature