反应详情

Morpholine (0.164 mL, 1.88 mmol, 1.1 eq.) and acetic acid (0.108 mL, 1.88 mmol, 1.1 eq.) were added to a solution of compound 19 (1.2 g, 1.71 mmol) in dry dichloromethane (20 mL) under N2 in an ice bath. Then NaHB(OAC)3 (0.508 g, 2.39 mmol, 1.4 eq.) was added in three equal portions in 10 minutes. After the addition, the reaction mixture was stirred for 3 hours at room temperature. A solution of saturated sodium bicarbonate (30 mL) was added to the reaction mixture and stirred at room temperature for 30 minutes. The organic layer was separated and washed sequentially with a solution of saturated sodium bicarbonate (20 mL), a solution of saturated sodium chloride, and dried over anhydrous sodium sulfate. The solvent was evaporated, and the residue was purified by silica gel chromatography eluting with CHCl3/MeOH (10:0.1) to give compound 20b as a white foam (0.921 g, 70%).

1. addition(0.508 g, 2.39 mmol, 1.4 eq.) was added in three equal portions in 10 minutes
2. additionAfter the addition
3. stirringstirred at room temperature for 30 minutes
4. customThe organic layer was separated
5. washwashed sequentially with a solution of saturated sodium bicarbonate (20 mL)
6. dry with materiala solution of saturated sodium chloride, and dried over anhydrous sodium sulfate
7. customThe solvent was evaporated
8. customthe residue was purified by silica gel chromatography
9. washeluting with CHCl3/MeOH (10:0.1)