1: 94 percent / aq. NaIO4 / methanol / 20 h / Ambient temperature 2: 1.) TFAA, 2.) BF3*Et2O / 1.) benzene, RT, 1 h, 2.) benzene, RT, 2 h 3: 57 percent / NaBH4, NiCl2*6H2O / methanol; tetrahydrofuran / 0.5 h / Ambient temperature View Scheme

1: 94 percent / aq. NaIO4 / methanol / 20 h / Ambient temperature 2: 1.) TFAA, 2.) BF3*Et2O / 1.) benzene, RT, 1 h, 2.) benzene, RT, 2 h 3: 57 percent / NaBH4, NiCl2*6H2O / methanol; tetrahydrofuran / 0.5 h / Ambient temperature 4: 10percent NaOH / ethanol / 18 h / Heating View Scheme