sodium tetrahydroborate in diethyl ether; hexane; isopropyl alcohol T=20°C; 3 h;

pyridinium chlorochromate in dichloromethane 3 h; Ambient temperature;

1: 93 percent / NaH / tetrahydrofuran / 1.) r.t., 30 min, 2.) r.t., 1 h 2: 96 percent / (i-Bu)2AlH / toluene / 1 h / -78 °C 3: 95 percent / PCC / CH2Cl2 / 3 h / Ambient temperature View Scheme

1: 96 percent / (i-Bu)2AlH / toluene / 1 h / -78 °C 2: 95 percent / PCC / CH2Cl2 / 3 h / Ambient temperature View Scheme