To a 25 mL screw top vial equipped with a stir bar was added HFIP (10 mL) and pyridine (1.58 g, 0.020 mol, 2 equiv) (CAUTION: mildly exothermic). The mixture was allowed to stir at room temperature for approximately five minutes. At this time the solution was poured into added to another 25 mL screw top vial equipped with a stir bar containing the toyslate  (4.93 g, 10.0 mmol) (CAUTION: mildly exothermic) and the vial was sealed. The biphasic reaction mixture was stirred at room temperature. Once the reaction was judged complete^1,2, the reaction mixture was transferred to a separatory funnel and diluted with pentane (≈ 100 mL) and deionized water (≈ 150 mL). The layers were separated and the aqueous layer was extracted twice with pentane (≈ 100 mL). The combined organic layers were washed with deionized water twice (≈ 100 mL) and one with brine (≈ 100 mL). The organic layer was dried with Na₂SO₄ and the solvent was removed in vacuo via rotary evaporation (50 mmHg, 30 ^oC water bath)³. Further purification was accomplished by flash column chromatography (hexanes) to give the pure CF₃ cyclopropane as a clear, colorless oil (1.07 g, 58%).