1: 77 percent / nickel(II) acetate, NaBH4, H2, ethylenediamine / ethanol 2: oxalic acid dihydrate, water / acetone / 1 h / Heating 3: diethyl ether / 0.25 h / 0 °C 4: 63 percent / mercury(II) acetate / 5.5 h / Ambient temperature 5: methylaluminum bis(2,6-diphenylphenoxide) (reagent B) / toluene / 0.5 h / -20 °C 6: NaBH4 / methanol / 0.08 h / Ambient temperature 7: pyridine, DMAP / CH2Cl2 / 0.5 h / Ambient temperature View Scheme

1: 77 percent / nickel(II) acetate, NaBH4, H2, ethylenediamine / ethanol 2: oxalic acid dihydrate, water / acetone / 1 h / Heating 3: diethyl ether / 0.25 h / 0 °C 4: 63 percent / mercury(II) acetate / 5.5 h / Ambient temperature 5: methylaluminum bis(2,6-diphenylphenoxide) (reagent B) / toluene / 0.5 h / -20 °C 6: NaBH4 / methanol / 0.08 h / Ambient temperature View Scheme