反应详情

Material from Step 4 (9.8 g, 20.78 mmol) was dissolved in a solution of 4 M HCl (51.9 mL, 208 mmol) in dioxane. The reaction mixture was stirred at room temperature for 1 hour. It was concentrated in vacuo, then dichloromethane was added and concentrated again in vacuo. The residue (1.75 g, 4.29 mmol) was dissolved in methanol (30 mL), and isovaleraldehyde (0.35 mL, 4.50 mmol) and acetic acid (0.25 mL, 4.29 mmol) were added. The reaction mixture was stirred at room temperature for 30 minutes. Sodium cyanoborohydride (0.323 g, 5.15 mmol) was then added to the mixture and it was stirred at room temperature overnight. The reaction mixture was concentrated, and partitioned between EtOAc and saturated aqueous NaHCO3 and extracted with EtOAc. The combined organics were washed with brine, dried over MgSO4, filtered and concentrated in vacuo to yield the title compound, which was used without further purification.

1. concentrationIt was concentrated in vacuo
2. additiondichloromethane was added
3. concentrationconcentrated again in vacuo
4. stirringThe reaction mixture was stirred at room temperature for 30 minutes
5. stirringwas stirred at room temperature overnight
6. concentrationThe reaction mixture was concentrated
7. custompartitioned between EtOAc and saturated aqueous NaHCO3
8. extractionextracted with EtOAc
9. washThe combined organics were washed with brine
10. dry with materialdried over MgSO4
11. filtrationfiltered
12. concentrationconcentrated in vacuo