反应详情

To 75A (1.00 g, 3.04 mmol) was added trimethyl(trifluoromethyl)silane (550 mg, 3.87 mmol) and cesium fluoride (10 mg, dried under high vacuum at 130° C. for 12 h). The mixture was stirred at rt for 24 h, and then was heated to 50° C. for 5 h. After cooling to rt, 4N HCl (ca. 10 mL) was added and the reaction was stirred overnight. The product was extracted with EtOAc (3×30 mL). The organic layer was washed with saturated aqueous NaHCO3 and brine, then dried (MgSO4), filtered and concentrated. The residue was purified via flash chromatography eluting with 0-15% ethyl acetate/hexane to provide (2R,3S)-3-(tert-butyl-dimethyl-silanyloxy)-2-[(1R)-(2,2,2-trifluoro-1-hydroxy-ethyl)]-pyrrolidine-1-carboxylic acid tert-butyl ester (75B) (357 mg) as a colorless oil and (2R,3S)-3-(tert-butyl-dimethylsilanyloxy)-2-[(1S)-(2,2,2-trifluoro-1-hydroxyethyl)]pyrrolidine-1-carboxylic acid tert-butyl ester (75C) (380 mg) as a white solid.

1. temperaturewas heated to 50° C. for 5 h
2. temperatureAfter cooling to rt
3. stirringthe reaction was stirred overnight
4. extractionThe product was extracted with EtOAc (3×30 mL)
5. washThe organic layer was washed with saturated aqueous NaHCO3 and brine
6. dry with materialdried (MgSO4)
7. filtrationfiltered
8. concentrationconcentrated
9. customThe residue was purified via flash chromatography
10. washeluting with 0-15% ethyl acetate/hexane