反应详情

A solution of Intermediate 151b (112 mg, 0.39 mmol) in EtOAc (2.1 mL) was treated with aqueous 1N NaOH (0.7 mL, 0.70 mmol) then 2,2,2-trichloroethyl chloroformate (0.056 mL, 0.41 mmol) and the mixture was stirred at RT for 2.5 h. The mixture was treated with another portion of 2,2,2-trichloroethyl chloroformate (0.015 mL, 0.11 mmol) and stirred at RT for a further 1 h. The mixture was diluted with EtOAc and water and the phases were separated. The aqueous layer was extracted with EtOAc (×2) and the combined organic phase was washed with brine, dried (Na2SO4), and concentrated in vacuo to give a pale red gum (195 mg). The gum was purified by FCC, using 0-40% EtOAc in cyclohexane, to give the title compound as a pale golden gum (134 mg, 74%). LCMS (Method 3): Rt 4.15 min, m/z 464.2, 466.2 [MH+].

1. customthe phases were separated
2. extractionThe aqueous layer was extracted with EtOAc (×2)
3. washthe combined organic phase was washed with brine
4. dry with materialdried (Na2SO4)
5. concentrationconcentrated in vacuo