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. 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
6. customThe residue is chromatographed over silica gel
7. washeluting with a gradient of hexanes to 10% ethyl acetate in hexanes
8. concentrationConcentration