反应详情

A solution of 7,7-dimethyl-1,4-dioxaspiro[4.5]decan-8-ol (1.0 equiv.) in 2.0 N hydrochloric acid aqueous solution (3.7 equiv.) and MeOH (0.9 M) was stirred at room temperature overnight. TLC (petroleum ether:ethyl acetate=3:1) showed that the reaction was completed. The solvent was removed under reduced pressure, the resulting residue was basified with saturated aqueous sodium bicarbonate solution and the aqueous layer was extracted with ethyl acetate. The combined organic layers were washed with brine, dried over anhydrous sodium sulfate and filtered. The filtrate was concentrated under vacuum to give 4-hydroxy-3,3-dimethylcyclohexanone (88% yield), which was used in the next step without further purification. 1H NMR (400 MHz, CDCl3) δ (ppm) 3.69-3.71 (m, 1H), 2.42-2.45 (m, 2H), 2.09-2.25 (m, 1H), 2.04-2.08 (m, 4H), 1.91-1.95 (m, 1H), 0.98 (s, 6H)

1. customThe solvent was removed under reduced pressure
2. extractionthe aqueous layer was extracted with ethyl acetate
3. washThe combined organic layers were washed with brine
4. dry with materialdried over anhydrous sodium sulfate
5. filtrationfiltered
6. concentrationThe filtrate was concentrated under vacuum