1,1-Dibromo-2-ethoxycyclopropane's synthesis: to a mixture of ethoxyethylene (1 equiv), n-Bu3N (0.024 equiv), and CHBr3 (1.5 equiv), is added aq. NaOH solution (50%, 6.25 equiv of NaOH) at rt. The reaction mixture is stirred for 48 h and poured into water and extracted with Et2O. The organic phase is washed with water, dried over anhydrous Na2SO4, filtered and concentrated using a rotary evaporator at 25 °C/60 mmHg. The residue is distilled at 25 °C/0.2 mmHg and further purified by silica gel column chromatography (petroleum ether/CH2Cl2 = 4:1) to give pure 1,1-dibromo-2-ethoxycyclopropane (1) (eq 1).
1
