反应详情

To a cooled (−60° C.) solution of 800 mg 19d in 10 mL THF was added 2.04 mmol n-butyllithium. After stirring at −60° C. for 30 min 877 mg N-fluorobenzenesulfonimide was added. The mixture was allowed to reach room temperature and was stirred for another 2 h. Water was added and the mixture was extracted with 2×ethyl acetate. The combined organic phases were dried and concentrated. The crude product by column chromatography over silica to afford an oil, which was crystallized from heptane/diisopropyl ethyl ether to give compound 340 mg of 27a as a pale yellow solid.

1. additionwas added
2. customto reach room temperature
3. extractionthe mixture was extracted with 2×ethyl acetate
4. customThe combined organic phases were dried
5. concentrationconcentrated
6. customThe crude product by column chromatography over silica to afford an oil, which
7. customwas crystallized from heptane/diisopropyl ethyl ether