反应详情

To a stirred mixture of NaH (60% in oil, 9.1 g, 0.228 mol) in DMSO (300ml) was added portionwise trimethylsulfoxonium iodide (53.9 g, 0.245 mol ) at the inner temperature with the range from 15° C. to 18° C. over 20 min. The ice bath was removed and the mixture was stirred at r.t. for 3 hrs. The mixture was cooled down to 10° C. To this mixture was added a solution of (2R)-2′,5′-Difluoro-2-(3,4,5,6-tetrahydro-2H-pyran-2-yloxy)-propiophenone (47.3 g, 0.175 mol) in DMSO (150 ml) dropwise over 20 min. The resulting mixture was stirred at r.t. for 4 hrs. The reaction mixture was poured into ice-water (800 ml). The whole was extracted with EtOAc (400 ml+200 ml×2). The combined organic layer was washed with brine, dried over Na2SO4 and concentrated in vacuo. The residue was chromatograkkphed on silicagel (n-hexane: EtOAc=8:1˜5:1) to give 2-(2,5-Difluorophenyl)-2-[(1R)-1-(3,4,5,6,-tetrahydro-2H-pyran-2-yloxy)ethyl]oxirane (48.3 g, 97% ).

1. customThe ice bath was removed
2. temperatureThe mixture was cooled down to 10° C
3. stirringThe resulting mixture was stirred at r.t. for 4 hrs
4. extractionThe whole was extracted with EtOAc (400 ml+200 ml×2)
5. washThe combined organic layer was washed with brine
6. dry with materialdried over Na2SO4
7. concentrationconcentrated in vacuo