Synthesis

To a stirred solution of 18-crown-6 (8.93 g, 33.78 mmol), THF (30 mL), and phosphite 1 (1.15 mL, 7.22 mmol) was added KHMDS (15.0 mL, 7.50 mmol, 0.5 M in toluene) by syringe in a dropwise manner at -78 ℃. After 15 min, benzyl bromide (0.40 mL, 3.36 mmol) was added to the round bottom flask at -78 oC. After continuous stirring over 4 hr at room temperature the general workup protocol was followed. The crude product was then purified by flash column chromatography (25% EtOAc in hexanes, Rf = 0.21 in 25% EtOAc in hexanes) yielding bis(2,2,2-trifluoroethyl) benzylphosphonate (635 mg, 1.89 mmol, 56.2%) as a white solid (mp = 68-71℃).