反应详情

温度

80 °C

N-iodosuccinimide (11.5 g, 50.9 mmol) was added to a solution of compound 237 (7.60 g, 46.3 mmol) in AcOH (90 mL). The reaction was warmed to 80° C. and stirred for 1.5 h. Solvent was removed in vacuo. The residue was taken up in dichloromethane (200 mL) and water. The aqueous layer was brought to pH 12 with 5 N NaOH and organics were sequestered. The aqueous was extracted further with dichloromethane (2×100 mL). The combined organics were treated with solid sodium thiosulfate, dried with MgSO4 and concentrated in vacuo. Silica gel chromatography (gradient elution 10 to 75% ethyl acetate in hexanes) afforded compound 238 (8.0 g, 60% yield).

1. customSolvent was removed in vacuo
2. extractionThe aqueous was extracted further with dichloromethane (2×100 mL)
3. additionThe combined organics were treated with solid sodium thiosulfate
4. dry with materialdried with MgSO4
5. concentrationconcentrated in vacuo
6. washSilica gel chromatography (gradient elution 10 to 75% ethyl acetate in hexanes)