反应详情

A solution of alcohol 77 (0.84 g, 2.2 mmol) in benzene (15 mL) was treated with 3,4-difluoro-phenol (402 mg, 3.1 mmol) and triphenylphosphine (864 mg, 3.3 mmol). To this solution was added DIAD (0.65 mL, 3.3 mmol) and the reaction mixture was stirred at ambient temperature. After 16 h, the solution was concentrated, diluted with DCM, washed with 1M NaOH, dried over anhydrous Na2SO4, filtered and concentrated. The aqueous phase was back-extracted with Et2O and the combined organic extracts were absorbed on SiO2 and purified by flash chromatography (3:1 hexane/EtOAc to 1:1 hexane/EtOAc) to afford 78 (0.86 g) which was contaminated with DIAD-related impurities and used without further purification.

1. concentrationthe solution was concentrated
2. additiondiluted with DCM
3. washwashed with 1M NaOH
4. dry with materialdried over anhydrous Na2SO4
5. filtrationfiltered
6. concentrationconcentrated
7. extractionThe aqueous phase was back-extracted with Et2O
8. customthe combined organic extracts were absorbed on SiO2
9. custompurified by flash chromatography (3:1 hexane/EtOAc to 1:1 hexane/EtOAc)