反应详情

To a solution of compound 20 (160 mg, 0.42 mmol) in THF (5 mL) and water at 0° C., was added a solution of lithium peroxide (prepared by adding 30% hydrogen peroxide (2.9 mL, 2.10 mmol) to lithium hydroxide (17.6 mg, 0.41 mmol) in water (0.679 mL)) dropwise. The mixture was stirred for 0° C. for 1h, quenched with sat.Na2SO3 (1.28 mL), solvent was removed in vacuo. The mixture was diluted with water and aqueous solution was extracted with DCM twice. The aq.layer was acidified with Conc.HCl and extracted with EtOAc twice. Combined organic layers were washed with brine and dried over MgSO4, concentrated. Purified by column chromatography (EtOAc/n-Hexane 40:60) to afforded compound 21 (80 mg, 86.9%) as a white solid. 1H NMR (CDCl3, 400 MHz) δ 1.51 (d, J=7.2 Hz, 3H), 4.27 (q, J=6.8 Hz, 1H), 7.16-7.24 (m, 2H), 7.37 (d, J=7.6 Hz, 1H)).

1. customquenched
2. customNa2SO3 (1.28 mL), solvent was removed in vacuo
3. additionThe mixture was diluted with water and aqueous solution
4. extractionwas extracted with DCM twice
5. extractionHCl and extracted with EtOAc twice
6. washCombined organic layers were washed with brine
7. dry with materialdried over MgSO4
8. concentrationconcentrated
9. customPurified by column chromatography (EtOAc/n-Hexane 40:60)