反应详情

Lithium hydroxide-H2O (0.293 g), the product of Step A (3.78 g), and methanol (8.4 mL) were combined in 245 mL of THF and stirred at room temperature. After 5 min 0.50 mL of acetic acid was added and the solution concentrated. The residue was diluted with ethyl acetate and this solution washed two times with aqueous sodium bicarbonate. The solution was concentrated and purified via flash chromatography on silica gel with a gradient elution of 0 to 55% ethyl acetate in methylene chloride. The product was then further purified by recrystallization from ethanol to afford the title compound. HPLC/MS: 499.0 (M+1), 500.8 (M+3); Rt=3.77 min.

1. concentrationthe solution concentrated
2. additionThe residue was diluted with ethyl acetate
3. washthis solution washed two times with aqueous sodium bicarbonate
4. concentrationThe solution was concentrated
5. custompurified via flash chromatography on silica gel with a gradient elution of 0 to 55% ethyl acetate in methylene chloride
6. customThe product was then further purified by recrystallization from ethanol