反应详情

温度

0 °C

4-(S)-Benzyl-3-(3-(R)-hydroxy-2-(S)-methyl-7-phenylheptanoyl)oxazolidin-2-one (7.64 g, 19 mmol) is dissolved in 4:1 THF-water (100 mL) and cooled to 0° C. To this is added 30% hydrogen peroxide (8.2 mL, 80 mmol) over 5 minutes, followed by lithium hydroxide monohydrate (1.3 g, 32 mmol) in water (40 mL) added dropwise over 10 minutes, keeping the reaction temperature <10° C. This mixture is stirred for 1 hour. Then sodium sulfite (10 g, 80 mmol), in 60 mL of water, is added carefully to keep the temperature <25° C. The solvent is removed in vacuo and the aqueous residue is washed with CH2Cl2 (3×100 mL). The aqueous layer is then cooled in an ice bath and acidified to pH 1 with 6 N HCl and the product extracted into ethyl acetate (2×100 mL). This solution is dried over MgSO4 and concentrated in vacuo, to yield (+)-(2S, 3R)-3-hydroxy-2-methyl-7-phenylheptanoic acid (3.76 g, 84%): m.p. 75-77° C.; [a]D23 +20° (c=1.0, CHCl3); 1H NMR (300 MHz, CDCl3) δ 7.30-7.25 (m, 2H), 7.20-7.16 (m, 3H), 3.95-3.93 (m, 1H), 2.65-2.54 (m, 3H), 1.69-1.34 (m, 6H), 1.20 (d, J=7.2 Hz, 3H); MS (EI) m/e 236 (M+).

1. additionadded dropwise over 10 minutes
2. customthe reaction temperature <10° C
3. customthe temperature <25° C
4. customThe solvent is removed in vacuo
5. washthe aqueous residue is washed with CH2Cl2 (3×100 mL)
6. temperatureThe aqueous layer is then cooled in an ice bath
7. extractionthe product extracted into ethyl acetate (2×100 mL)
8. dry with materialThis solution is dried over MgSO4
9. concentrationconcentrated in vacuo