1: 75 percent / NaBH4, cerous chloride / ethanol; tetrahydrofuran / 1 h / -78 - -70 °C 2: 52 percent / Ph3P, DEAD / tetrahydrofuran / a) -10 to -15 deg C, 1 h, b) ice-bath temp., 18 h 3: 74 percent / hydrazine monohydrate / methanol; tetrahydrofuran / 3 h / Ambient temperature 4: 62 percent / Na, NH3 liq. / tetrahydrofuran / 2 h / -70 - -65 °C View Scheme

Multi-step reaction with 3 steps 1: 75 percent / NaBH4, cerous chloride / ethanol; tetrahydrofuran / 1 h / -78 - -70 °C2: 52 percent / Ph3P, DEAD / tetrahydrofuran / a) -10 to -15 deg C, 1 h, b) ice-bath temp., 18 h3: 74 percent / hydrazine monohydrate / methanol; tetrahydrofuran / 3 h / Ambient temperature