反应详情

A solution of the compound of example 50 (2.40 g, 6.07 mmol) in anhydrous THF (60 mL) was cooled to −78° C. A solution of NaHDMS in THF (1M, 6.7 mmol, 6.7 mL) was injected over 10 minutes. The reaction mixture was stirred for an additional 20 minutes, after which time, a solution of tert-butyl bromoacetate in anhydrous THF (5 mL) was slowly injected. After stirring for 1 h at −78° C., and 3 h at −48° C., the reaction was quenched by the addition of a saturated ammonium chloride solution. The mixture was extracted several times using ethyl acetate. The recombined organic layer was extracted successively with brine, saturated sodium hydrogen carbonate, brine and water. The solvent was evaporated following drying over sodium sulfate and filtration. The resultant crude material was flashed using 20% ethyl acetate in hexanes to give the product as a white solid. 1H-NMR(CDCl3, 300 MHz: 1.40, 1.41(2s, 9H); 1.74-1.92(m, 5H); 2.45-2.95(m, 4H); 3.31(m, 1H); 3.69, 3.73(2s, 3H); 4.11(m, 2H); 4.50, 4.66(2m, 1H); 7.25(m, 10H).

1. stirringAfter stirring for 1 h at −78° C.
2. custom3 h at −48° C., the reaction was quenched by the addition of a saturated ammonium chloride solution
3. extractionThe mixture was extracted several times
4. extractionThe recombined organic layer was extracted successively with brine, saturated sodium hydrogen carbonate, brine and water
5. customThe solvent was evaporated
6. dry with materialfollowing drying over sodium sulfate and filtration