反应详情

温度

-40 °C

To a stirred solution of tert-butyl 4-iodobenzoate (0.304 g, 1.0 mmol) in 10 mL THF at −40° C. was added a solution of isopropylmagnesium bromide (1.05 ml, 1.05 mmol, 1M in THF) dropwise under argon. After stirring for 1 hour at −40° C., ethyl benzoylformate (0.175 ml, 1.1 mmol) was added dropwise and the cold bath allowed to warm to room temperature over a 40 min. period. The reaction was quenched by the addition of an aqueous solution of 20% ammonium chloride. The reaction mixture was extracted twice with ether, the combined organic layers washed with brine, dried over Na2SO4 and was evaporated to give an oil that was chromatographed on 10 g silica gel using a gradient elution from 0-40% EtOAc in Hexanes. Product containing fractions were combined and concentrated to give (0.078 g, 22%) ethyl (4-tert-butyloxycarbonylphenyl)(hydroxy)phenylacetate as a colorless oil. NMR, 400 MHz (CDCl3) 7.95 ppm (d, J=8.55 Hz, 2H), 7.52 ppm (d, J=8.55 Hz, 2H), 7.30-7.40 ppm (m, 5H), 4.33 ppm (q, J=7.08 Hz, 2H), 4.29 ppm (s, OH, 1H), 1.59 ppm (s, 9H), 1.28 ppm (t, J=7.08 Hz, 3H).

1. temperatureto warm to room temperature over a 40 min. period
2. customThe reaction was quenched by the addition of an aqueous solution of 20% ammonium chloride
3. extractionThe reaction mixture was extracted twice with ether
4. washthe combined organic layers washed with brine
5. dry with materialdried over Na2SO4
6. customwas evaporated
7. customto give an oil that
8. customwas chromatographed on 10 g silica gel using
9. washa gradient elution from 0-40% EtOAc in Hexanes
10. additionProduct containing fractions
11. concentrationconcentrated