反应详情

Under an argon atmosphere, DMAP (259 mg, 2.12 mmol) and acetic anhydride (3 ml, 31.75 mmol) were added to a solution of (±)-6-(2'-hydroxyethyl)-1,4-dioxaspiro [4.5)decane (3.94 g, 21.17 mmol) in pyridine (106 ml). The mixture was stirred at room temperature for 1 h. The pyridine was evaporated under reduced pressure and the residue was diluted with methanol (100 ml). The mixture was cooled to 0° C. and 2 M hydrochloric acid (250 ml) was added. The mixture was stirred at room temperature for 1 h and then extracted with chloroform (3×200 ml). The combined organic extracts were washed with 2 M hydrochloric acid (200 ml) and brine (300 ml). The organic phase was dried over magnesium sulphate and the solvent was evaporated under reduced pressure to give the crude product which was purified using flash column chromatography with hexane-ethyl acetate (3:1) to give (±)-2-(2'acetoxyethyl)cyclohexanone (3.45 g, 88% yield) as a colourless oil. Rf 0.34 (hexane-ethyl acetate, 7:3).

1. customThe pyridine was evaporated under reduced pressure
2. additionthe residue was diluted with methanol (100 ml)
3. temperatureThe mixture was cooled to 0° C.
4. addition2 M hydrochloric acid (250 ml) was added
5. stirringThe mixture was stirred at room temperature for 1 h
6. extractionextracted with chloroform (3×200 ml)
7. washThe combined organic extracts were washed with 2 M hydrochloric acid (200 ml) and brine (300 ml)
8. dry with materialThe organic phase was dried over magnesium sulphate
9. customthe solvent was evaporated under reduced pressure
10. customto give the crude product which
11. customwas purified