Synthesis
KHMDS (7.50 mL, 3.75 mmol, 0.5 M in toluene) was added to a solution of 18-
crown-6 (4.10 g, 15.51 mmol), THF (20 mL), and bis (2,2,2-trifluoroethyl) phosphite (1)
(0.50 mL, 3.41 mmol) by syringe in a dropwise manner at -78 ℃. Following 15 min,
ethyl 2-bromopropionate (0.40 mL, 3.08 mmol) was added to the round bottom flask and
the reaction mixture was allowed to stir for 4 hr at room temperature. Following the
standard workup procedure, the crude product was then purified by flash column
chromatography (3:1 to 2:1 hexanes:EtOAc, Rf
= 0.33 in 1:1 hexanes:EtOAc) yielding
Ethyl 2-[Bis(2,2,2-trifluoroethyl)phosphono] Propionate (112 mg, 0.33 mmol, 10.5%) as a yellow syrup.
