反应详情

温度

-78 °C

n-BuLi (1.6M in hexane, 1.5 mL, 2.4 mmol) was slowly added to 2,2,6,6-tetramethylpiperidine at 0° C. and the slurry was stirred 10 min, then cooled to -78° C. and diluted with 6 mL (oxygenated) THF. The ester from Example 3, Step 2 (880 mg, 1.92 mmol) dissolved in 3 mL THF (O2) was added and the resulting mixture was stirred-- h at -78° C. and 1 h at -45° C. HMPA (668 μL, 3.8 mmol) was added and the mixture was stirred another 2 h at -30° C., then warmed to 0° C. The reaction was quenched with aq. NaHSO3 and then partitioned between saturated NH4Cl and ethyl acetate; the organic layer was washed with water, brine and dried over MgSO4. Purification by flash chromatography (40% ethyl acetate in hexane) provided 230 mg of the title compound.

1. additionwas added
2. stirringthe resulting mixture was stirred-- h at -78° C. and 1 h at -45° C
3. stirringthe mixture was stirred another 2 h at -30° C.
4. temperaturewarmed to 0° C
5. customThe reaction was quenched with aq. NaHSO3
6. custompartitioned between saturated NH4Cl and ethyl acetate
7. washthe organic layer was washed with water, brine
8. dry with materialdried over MgSO4
9. customPurification by flash chromatography (40% ethyl acetate in hexane)