反应详情

A solution of silver nitrate (5.76 g, 33.9 mmol) in 20 ml H2O was added to a solution of the product of STEP 4 (3.8 g, 16.9 mmol) in 80 ml ethanol. A solution of Sodium hydroxide (2.71 g, 67.7 mmol) in 10 ml H2O was added dropwise at room temperature. After 2 h, the reaction was filtered through a short column of Celite®. The filtrate was diluted with H2O and extracted with ether (3×30 ml). The aqueous layer was acidified with concentrated HCl and extracted with chloroform. Chloroform layer was dried with MgSO4 and concentrated. The residue was dissolved in 50 ml ethanol and 25 ml 4N HCl/dioxane solution. It was stirred at room temperature for 60 h and then concentrated to afford a colorless oil in 4.14 g. NMR spectra of the product were consistent for the proposed structure.

1. filtrationthe reaction was filtered through a short column of Celite®
2. additionThe filtrate was diluted with H2O
3. extractionextracted with ether (3×30 ml)
4. extractionextracted with chloroform
5. dry with materialChloroform layer was dried with MgSO4
6. concentrationconcentrated
7. dissolutionThe residue was dissolved in 50 ml ethanol
8. concentrationconcentrated
9. customto afford a colorless oil in 4.14 g