Equip a 1000 mL oven-dried three-necked round-bottom flask with a magnetic stir bar, an attached constant-pressure funnel, and a gas outlet. Connect the gas outlet to an empty 500 mL spare trap, which is then connected to the outlet of an inverted glass funnel located directly above a 1000 mL beaker containing 120 g NaOH in 600 mL of water. Add anhydrous methanol (160 g) to the flask. Add tetrafluoroethane-β-sulfonyl lactone (440 g) dropwise to the mixture through a feeding funnel with stirring. Cool the mixture in an ice bath for 3 hours. After the addition is complete, gradually heat the reaction mixture to room temperature. Stir the mixture overnight at room temperature.
After purging with nitrogen for 1 hour to completely remove residual HF from the system, the resulting reaction mixture was washed with water (2 × 400 mL) and brine (2 × 400 mL) to remove residual methanol. The organic phase was collected and dried over anhydrous sodium sulfate. After filtration, the crude product was purified by distillation.
