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

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