反应详情

A solution of ethyl 2-chloro-3-oxo-3-phenylpropionate (CI, 100 g, 0.44 mol) and glacial acetic acid (25 ml, 0.44 mol) in ethanol 1 l) is cooled to −5° and stirred for 10 min. Sodium borohydride pellets (12.54 g, 0.33 mol, diam. 11 mm) are added in portions (4.2 g×3) with vigorous stirring. The reaction temperature is maintained at −5 to 0°. After the addition, the reaction mixture is stirred continuously at 0° for 5 hr and is then poured slowly into ice-water with stirring. The mixture is extracted with ethyl acetate (1 l). The organic phase is washed three times with water (100 ml) and saline (100 ml), dried over magnesium sulfate, and the solvent is removed under reduced pressure to give the title compound as a 1:4 mixture of the anti and syn isomers as determined by NMR, MS (m/z, CI+NH3) 246 (M++17), 228 (M+), 210, 194; “Anti” NMR (500 MHz, CDCl3) 7.60-7.50, 5.33, 4.64, 4.33, 1.33 δ;. CMR (300 MHz, CDCl3) 167.9, 138.2, 128.7, 128.5, 126.7, 74.6, 62.9, 62.2 and 13.7 δ; “Syn” NMR (500 MHz, CDCl3) 7.60-7.50, 5.24, 4.58, 4.44 and 1.46 δ; CMR (300 MHz, CDCl3) 168.9, 138.8, 126.7, 126.5, 126.9, 75.2, 62.3, 59.2 and 13.8 δ.

1. additionare added in portions (4.2 g×3) with vigorous stirring
2. temperatureThe reaction temperature is maintained at −5 to 0°
3. additionAfter the addition
4. stirringthe reaction mixture is stirred continuously at 0° for 5 hr
5. stirringwith stirring
6. extractionThe mixture is extracted with ethyl acetate (1 l)
7. washThe organic phase is washed three times with water (100 ml) and saline (100 ml)
8. dry with materialdried over magnesium sulfate
9. customthe solvent is removed under reduced pressure