BIS(2,2,2-TRIFLUOROETHYL) (METHOXYCARBONYLMETHYL)PHOSPHONATE

Chemical Properties

clear orange to dark orange-brown liquid

Uses

Methyl?P,P-bis(2,2,2-trifluoroethyl)phosphonoacetate can be used:

• In one of the key synthetic steps for the preparation of?trans-hydrindanes and (R)-(+)-umbelactone.
• To prepare a cis-olefinic ester derivative by Still–Gennari olefination of an aldehyde derivative using 18-crown ether and potassium bis(trimethylsilyl)amide (KHMDS).
• In the synthesis of (?)-(6S,2′S)-epi?cryptocaryalactone.

Synthesis

The synthesis method of Bis(2,2,2-trifluoroethyl) (Methoxycarbonylmethyl) phosphonate is as follows: To a stirred solution of dried 18-crown-6 (4.53 g, 17.14 mmol), THF (20 mL), and Bis(2,2,2-trifluoroethyl) Phosphite (0.70 mL, 1.29 mmol), was added KHMDS (9.0 mL, 4.50 mmol, 0.5M in toluene) by syringe in a dropwise manner at -78 ℃. After 15 min, methyl chloroacetate (0.30 mL, 3.41 mmol) was added and the reaction mixture was allowed to stir for 4 hr at room temperature. The reaction mixture was diluted with EtOAc (20 mL) and then quenched with sat. ammonium chloride (50 mL). The aqueous layer was extracted with EtOAc (3 x 30 mL). The combined organic extracts were dried under anhydrous magnesium sulfate. Following filtration, the solvents were removed in vacuo. The crude product was then purified by flash column chromatography (33% EtOAc in hexanes, Rf = 0.22 in 33% EtOAc in hexanes) yielding Bis(2,2,2-trifluoroethyl) (Methoxycarbonylmethyl)phosphonate (766 mg, 2.41 mmol, 70.3%) as a yellow syrup.