反应详情

温度

-78 °C

To a stirred solution of (R)-2-(trityl-amino)-butyraldehyde (1.5 g, 1 eq, 4.53 mmol) in Et2O (150 mL) under an argon atmosphere at −78° C., was added ethylmagnesium bromide (3 M in Et2O, 1.51 mL, 1 eq, 4.53 mmol) dropwise. The solution was stirred at −78° C. for 2 h, then allowed to warm to room temperature over 16 h. The mixture was recooled to 0° C., H2O (150 mL) added, and the organic phase separated. The aqueous phase was extracted with more Et2O (2×50 mL), and the combined organic phase washed with brine (50 mL), dried (MgSO4) and evaporated in vacuo. The residue was purified by silica gel column chromatography, eluted with hexane:ether (90:10) to afford the title compound as a light yellow oil. Yield: 1.19 g (73%). (65% de 3R,4S: 35% de 3S,4S). 1H-NMR (d6-DMSO, 250 MHz): δ 0.46+0.69 (t & m, 6H, J=7.34 Hz, —NHCH(CH2CH3)CH(CH2CH3)OH), 1.13-1.29 (m, 4H, —NHCH(CH2CH3)CH(CH2CH3)OH), 2.17 (m, 1H, —NHCH(CH2CH3)CH(CH2CH3)OH), 2.55 (m, 1H, —NHCH(CH2CH3)CH(CH2CH3)OH), 3.20-3.39 (m, 1H, —NHCH(CH2CH3)CHCH2CH3)OH), 4.29 & 4.39 (2×d, 1H, J=4.74 & 5.53 Hz, —NHCH(CH2CH3)CH(CH2CH3)OH), 7.15-7.52 (m, 15H, 3×Ph).

1. temperatureto warm to room temperature over 16 h
2. customwas recooled to 0° C.
3. customthe organic phase separated
4. extractionThe aqueous phase was extracted with more Et2O (2×50 mL)
5. washthe combined organic phase washed with brine (50 mL)
6. dry with materialdried (MgSO4)
7. customevaporated in vacuo
8. customThe residue was purified by silica gel column chromatography
9. washeluted with hexane:ether (90:10)