反应详情

To a stirred suspension of CuBr.SMe2 (1.54 g, 7.5 mmol) in anhydrous ether under an argon atmosphere at −78° C., was added methyllithium (1.6M in ether, 9.4 ml, 15 mmol) dropwise. After the addition was complete, the reaction was allowed to warm to room temperature. The reaction was recooled to −78° C. and a solution of (S)-2-(dibenzylamino)butanal (1 g, 3.75 mmol) in ether (20 ml) was added dropwise. After the addition, continued stirring for 2 h The reaction was then quenched with a saturated aqueous solution of NH4Cl (10 ml). The reaction mixture was extracted with ether (2×30 ml) and the combined organic phase washed with brine (20 ml), dried (MgSO4) and evaporated in vacuo. The residue was purified by flash silica gel gradient column chromatography, eluted with hexane:ethyl acetate (100:0→80:20) to afford the product as a light yellow oil (0.95 g, 89%) as the only isomer. δH (250 MHz, CDCl3) 1.05 (3 H, t, J 7.5, CHCH2CH3), 1.25 [3 H, d, J 7.5, CH(CH3)OH], 1.6-1.49 (1 H, m, CHHCH3), 1.88-1.73 (1 H, m, CHHCH3), 2.41 (1 H, s, br, OH), 2.66-2.59 (1 H, m, CHCH2CH3), 3.85-3.65 (4 H, m, 2×CH2Ph), 4.05-3.9 (1 H, m, CHOH), 7.41-7.25 (10 H, m, ArH) δC (250 MHz, CDCl3) 140.05 (2×C), 128.98 (4×CH), 128.37 (4×CH), 127.3 (2×CH), 66.81 (CH), 63.65 (CH), 55.41 (CH2), 20.63 (CH3) 18.44 (CH2), 12.5 (CH3)

1. additionAfter the addition
2. customwas recooled to −78° C.
3. additionAfter the addition
4. customwas then quenched with a saturated aqueous solution of NH4Cl (10 ml)
5. extractionThe reaction mixture was extracted with ether (2×30 ml)
6. washthe combined organic phase washed with brine (20 ml)
7. dry with materialdried (MgSO4)
8. customevaporated in vacuo
9. customThe residue was purified by flash silica gel gradient column chromatography
10. washeluted with hexane:ethyl acetate (100:0→80:20)