反应详情

A solution of ethyl 2,4,6-trifluorophenylacetate (436 mg, 2.0 mmol) in 3 mL of tetrahydrofuran is cooled to −78° C., and lithium diisopropylamide (2.0 M in heptane/tetrahydrofuran/ethylbenzene, 1.0 mL, 2.0 mmol) is added dropwise with stirring. The mixture is stirred at −78° C. for 1 h, and cycloheptanecarboxylic acid chloride (321 mg, 2.0 mmol) is added dropwise. The mixture is warmed to room temperature and acidified with 2 mL of 1.0 N hydrochloric acid. The product is extracted with ethyl acetate. The organic layer is washed with saturated sodium chloride, dried over magnesium sulfate, and concentrated to a residue. The residue is chromatographed over silica gel, eluting with a gradient of hexanes to 10% ethyl acetate in hexanes. Concentration provides ethyl 3-cycloheptyl-3-oxo-2-(2,4,6-trifluorophenyl)propanoate as a colorless oil (410 mg). MS: m/z 341.2 (M−H).

1. stirringThe mixture is stirred at −78° C. for 1 h
2. extractionThe product is extracted with ethyl acetate
3. washThe organic layer is washed with saturated sodium chloride
4. dry with materialdried over magnesium sulfate
5. concentrationconcentrated to a residue
6. customThe residue is chromatographed over silica gel
7. washeluting with a gradient of hexanes to 10% ethyl acetate in hexanes
8. concentrationConcentration