In a 250 mL oven-dried round-bottom flask with a stir bar, was added 50 mmol, 2.5 equiv) under nitrogen atmosphere. DCM (120 mL, 0.1 M) was added into the flask and the reaction mixture was cooled to -40 °C. ZnEt2 (1.0 M, 12.5 mL, 12.50 mmol, 2.5 equiv) was added slowly into the flask by syringe and the reaction mixture was stirred at this temperature for 15 min. CH2I2 .00 mmol, 4.0 equiv) was added slowly by syringe and the reaction mixture was stirred at this temperature for another 15 min. Next, the corresponding solution of alkene 7a (741.0 mg, 5.00 mmol, 1.0 equiv) in DCM (20 mL) was added by syringe and the reaction mixture was allowed to warm to room temperatureand stirred for 16 h. After the reaction reached completion (as judged by 1H-NMR), the reaction mixture was quenched with sat. NH4Cl (60 mL) for 30 minutes and extracted with DCM (100mL) for 3 times. The combined organic layers were washed with aq. NaOH (1.0 M, 60 mL) and brine (40 mL), dried over Na2SO4 and filtered. The resulted mixture was concentrated under reduced pressure, the crude residue was purified by column chromatography (Pentane : EtOAc = 50: 1 to 10: 1) to afford the desired compound 1methoxy-4-(2-methylcyclopropyl)benzene 1i (389 mg, 2.40 mmol, 48%) as colorless oil.