反应详情

温度

-78 °C

To a solution of the intermediate obtained in Step 2 (7.7 g, 21.8 mmol) in THF (80 mL), at −78° C. was added n-BuLi (21.8 mL, 54.4 mmol) dropwise, and stirred for additional 15 min. at −78° C. after the addition. Benzyl chloroformate (4.7 mL, 32.6 mmol) was then added and the resulting mixture was stirred for 10 min before the cooling bath was removed. The mixture was allowed to warm to room temperature while stirring. The reaction was quenched with a solution of NH4Cl (5 mL), diluted with ethyl ether (150 mL), washed with water (2×30 mL) and brine (30 mL). After drying with Na2SO4, the solvent was removed and the residue was chromatographed (silica gel, ethylacetate in hexanes, 0-5%) to provide product as white crystalline material (6.9 g, yield: 65%).

1. additionafter the addition
2. stirringthe resulting mixture was stirred for 10 min before the cooling bath
3. customwas removed
4. temperatureto warm to room temperature
5. stirringwhile stirring
6. customThe reaction was quenched with a solution of NH4Cl (5 mL)
7. additiondiluted with ethyl ether (150 mL)
8. washwashed with water (2×30 mL) and brine (30 mL)
9. dry with materialAfter drying with Na2SO4
10. customthe solvent was removed
11. customthe residue was chromatographed (silica gel, ethylacetate in hexanes, 0-5%)