反应详情

温度

25 °C

Silver nitrate (1.87 g, 11.0 mmol) was dissolved in 3 ml H2O. It was added to a solution of the product from STEP 6 (1.6 g, 5.5 mmol) in 25 ml ethanol. A solution prepared from dissolving NaOH (0.88 g, 22.0 mmol) in 4.0 ml H2O was added dropwise to the silver nitrate solution. The reaction was stirred at 25° C. for 2 h. The reaction was diluted with 15 ml H2O. The ethanol was removed and the resulting residue was extracted with ethyl acetate (2×60 ml). The aqueous extracts were acidified with 1 N aqueous HCl solution to PH=5, and extracted with ethyl acetate (3×100 ml). The organic layer was washed with 15 ml brine, dried with MgSO4, filtered and concentrated to afford a 1.1 g of clean oil. The oil was dissolved in 30 ml ethanol and 15 ml 2M HCl/dioxane. The reaction was stirred at room temperature for 18 h and concentrated. The residue was purified by chromatography (on silica gel, CH2Cl2/MeOH/NH4OH=95/5/0.1) to give 0.88 g of a gummy solid. The 1H NMR spectrum of the product was consistent for the proposed structure.

1. customA solution prepared
2. customThe ethanol was removed
3. extractionthe resulting residue was extracted with ethyl acetate (2×60 ml)
4. extractionextracted with ethyl acetate (3×100 ml)
5. washThe organic layer was washed with 15 ml brine
6. dry with materialdried with MgSO4
7. filtrationfiltered
8. concentrationconcentrated