反应详情

In a 500 mL flask charged with methyl ester from step C above (20 g, 74 mmol) in THF (250 mL) was added MeOH (100 mL) and aq. 3N NaOH (74 mmol, 25 mL). The mixture was stirred overnight at rt and an additional 15 mL NaOH added. Reaction stirred for 16 h, the pH was then adjusted 4-5 and the mixture extracted repeatedly with EtOAc. The combined organic layers were washed with brine, dried over Na2SO4 and concentrated to dryness to give 18.5 g of product as a white solid.

1. customReaction
2. stirringstirred for 16 h
3. extractionthe mixture extracted repeatedly with EtOAc
4. washThe combined organic layers were washed with brine
5. dry with materialdried over Na2SO4
6. concentrationconcentrated to dryness