反应详情

A solution of Silver Nitrate (0.722 g, 4.25 mmol) in 2.0 ml H2O was added to a solution of the product of STEP 4 (0.775 g, 2.04 mmol) in 20 ml ethanol. A solution of sodium hydroxide (2.71 g, 67.7 mmol) in 3.0 ml H2O was added dropwise at room temperature. After 6 h, the reaction was filtered through a short column of Celite® and washed with H2O. The filtrate was extracted with ether (3×30 ml). The aqueous layer was acidified with concentrated HCl and extracted with chloroform. The organic layer was dried with MgSO4, concentrated and dried in vacuo. The residue (0.75 g) was dissolved in 15 ml ethanol and 15 ml 4N HCl in dioxane. The reaction was stirred at room temperature for 18 h and concentrated. The residue was purified by chromatography (on silica gel, ethyl acetate/hexane=3/7) to afford a pale brown oil in 0.536 g. NMR spectra of the product were consistent for the proposed structure.

1. filtrationthe reaction was filtered through a short column of Celite®
2. washwashed with H2O
3. extractionThe filtrate was extracted with ether (3×30 ml)
4. extractionextracted with chloroform
5. dry with materialThe organic layer was dried with MgSO4
6. concentrationconcentrated
7. customdried in vacuo
8. dissolutionThe residue (0.75 g) was dissolved in 15 ml ethanol
9. concentrationconcentrated
10. customThe residue was purified by chromatography (on silica gel, ethyl acetate/hexane=3/7)
11. customto afford a pale brown oil in 0.536 g