反应详情

A solution of 1H-tetrazole (2.37 g, 33.9 mmol, 3.0 equiv), di-tert-butyl-N,N-diisopropylphosphoramidite (7.42 mL, 22.6 mmol, 2.0 equiv), and ethyl(2R)-4-(4′-hydroxybiphenyl-4-yl)-2-methyl-2-(methylsulfonyl)butanoate (4.25 g, 11.3 mmol, 1.0 equiv) in tetrahydrofuran (113 mL) was allowed to stir overnight at room temperature. A solution of saturated sodium sulfite (330 mL) was added, and the mixture was extracted with dichloromethane (3×440 mL). The combined organic layers were washed with water (3×330 mL), brine (3×330 mL), dried over anhydrous sodium sulfate, filtered and concentrated under reduced pressure. The crude material was purified by flash chromatography on silica gel (50% ethyl acetate in heptane) to provide a colorless oil (5.84 g, 91%). 1H NMR (400 MHz, CHLOROFORM-d) δ ppm 1.33 (t, J=7.13 Hz, 3H) 1.50-1.52 (m, 18H) 1.71 (s, 3H) 2.17-2.30 (m, 1H) 2.46-2.61 (m, 2H) 2.72-2.85 (m, 1H) 3.04 (s, 3H) 4.26 (qd, J=7.13, 1.27 Hz, 2H) 7.21-7.28 (m, 4H) 7.45-7.53 (m, 4H).

1. extractionthe mixture was extracted with dichloromethane (3×440 mL)
2. washThe combined organic layers were washed with water (3×330 mL), brine (3×330 mL)
3. dry with materialdried over anhydrous sodium sulfate
4. filtrationfiltered
5. concentrationconcentrated under reduced pressure
6. customThe crude material was purified by flash chromatography on silica gel (50% ethyl acetate in heptane)