1: 77 percent / LiAlH4 / tetrahydrofuran / 5 h / Ambient temperature 2: BF3*Et2O / diethyl ether / 3 h / Ambient temperature View Scheme

1: 77 percent / LiAlH4 / tetrahydrofuran / 5 h / Ambient temperature 2: BF3*Et2O / diethyl ether / 3 h / Ambient temperature 3: 48.3 percent / CrO3 / pyridine; CH2Cl2 / 1.) 0 deg C, 20 min, 2.) 23 deg C, 20 min View Scheme

lithium aluminium tetrahydride in tetrahydrofuran 5 h; Ambient temperature;

1: 77 percent / LiAlH4 / tetrahydrofuran / 5 h / Ambient temperature 2: BF3*Et2O / diethyl ether / 3 h / Ambient temperature View Scheme