反应详情

温度

-78 °C

To Intermediate 18c (495.7 mg, 1.08 mmol) in THF at −78° C. was added LiHMDS (2.268 mL, 2.268 mmol) dropwise. After 10 min, tert-butyl bromoacetate was added and the mixture was stirred at −78° C. for 20 min. It was allowed to warm to −40° C. over 20 min, then quenched with NH4Cl. The reaction mixture was diluted with EtOAc, then washed with H2O, brine, dried (Na2SO4) and concentrated. It was purified by SiO2 chromatography (50% EtOAc/hexanes) to afford 367.9 mg (59%) of intermediate 38a.

1. temperatureto warm to −40° C. over 20 min
2. customquenched with NH4Cl
3. additionThe reaction mixture was diluted with EtOAc
4. washwashed with H2O, brine
5. dry with materialdried (Na2SO4)
6. concentrationconcentrated
7. customIt was purified by SiO2 chromatography (50% EtOAc/hexanes)