1: 1) sec-BuLi, N,N,N',N'-tetramethylethylenediamine / 1) cyclohexane, THF, -105 deg C, 20 min 2) THF, -105 deg C, 1h 2: 52 percent / 90percent HCO2H / 1 h / Heating 3: 18 percent / BBr3 / CH2Cl2 / 480 h / Ambient temperature View Scheme

1: 1) sec-BuLi, N,N,N',N'-tetramethylethylenediamine / 1) cyclohexane, THF, -105 deg C, 20 min 2) THF, -105 deg C, 1h 2: Bu4NF / tetrahydrofuran / 0.17 h / Ambient temperature 3: K2CO3 / acetone / 4 h / Heating 4: 30 percent / 90percent HCO2H / 4 h / Heating View Scheme