反应详情

To a solution of compound 55 (25.0 g, 89.4 mmol) in THF (100 mL), H2O (100 mL) and MeOH (100 mL) was added aq. 5 N NaOH dropwise at 0° C. The mixture was stirred at room temperature for 1 hour. Conc. HCl was added to the mixture to acidify and the mixture was extracted with EtOAc (500 mL×2). The combined organic layers were dried over MgSO4, filtered and concentrated in vacuo to afford the crude acid 56 (22.6 g, 96%) as an orange solid.

1. extractionthe mixture was extracted with EtOAc (500 mL×2)
2. dry with materialThe combined organic layers were dried over MgSO4
3. filtrationfiltered
4. concentrationconcentrated in vacuo