1: 1.) TFAA; 2.) BF3*Et2O / 1.) benzene, RT, 1 h; 2.) benzene, RT, 1 h 2: 89 percent / NaBH4, NiCl2*6H2O / methanol; tetrahydrofuran / 0.5 h / Ambient temperature 3: 92 percent / aq. NaOH / ethanol / 20 h / Heating View Scheme

1: 1.) TFAA; 2.) BF3*Et2O / 1.) benzene, RT, 1 h; 2.) benzene, RT, 1 h 2: 89 percent / NaBH4, NiCl2*6H2O / methanol; tetrahydrofuran / 0.5 h / Ambient temperature 3: 90 percent / LiAlH4 / tetrahydrofuran / Heating View Scheme