1: 88 percent / tetrahydrofuran; hexane / 3 h / -78 °C 2: 90 percent / CAN / H2O; acetonitrile / 6 h / 0 °C 3: liq. NH3; Na / tetrahydrofuran / 2 h / -78 °C 4: 70.0 mg / NaBH4 / tetrahydrofuran; H2O / 0.5 h 5: BCl3 / CH2Cl2 / 0.5 h / 0 °C 6: BOPCl; TEA / CH2Cl2 / 16 h / 20 °C 7: 6.8 mg / PH3PCl2 / pyridine; acetonitrile / 4 h / 20 °C View Scheme