反应详情

To a solution of 1,4-dioxaspiro[4.5]decan-8-one (1.0 equiv.) in anhydrous THF (0.6 M) was added sodium hydride (2.0 equiv, 60% in mineral oil) at 0° C. under nitrogen. After the resulting reaction mixture was stirred at room temperature for 60 min, iodomethane (2.5 equiv.) was added. The reaction was stirred at 10° C. overnight. TLC (petroleum ether:ethyl acetate=10:1) showed that the reaction was completed. The reaction was quenched with saturated aqueous ammonium chloride 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, and the residue was purified by silica gel column chromatography (10% ethyl acetate in petroleum ether) to afford the 7,7-dimethyl-1,4-dioxaspiro[4.5]decan-8-one (40% yield) as colorless oil. 1H NMR (400 MHz, CDCl3) δ (ppm) 3.99 (s, 4H), 2.55-2.58 (m, 2H), 1.97-2.00 (m, 2H), 1.87 (s, 2H), 1.16 (s, 6H).

1. customAfter the resulting reaction mixture
2. stirringThe reaction was stirred at 10° C. overnight
3. customThe reaction was quenched with saturated aqueous ammonium chloride solution
4. extractionthe aqueous layer was extracted with ethyl acetate
5. washThe combined organic layers were washed with brine
6. dry with materialdried over anhydrous sodium sulfate
7. filtrationfiltered
8. concentrationThe filtrate was concentrated under vacuum
9. customthe residue was purified by silica gel column chromatography (10% ethyl acetate in petroleum ether)