反应详情

8-[2,4-Bis(methoxymethoxy)phenyl]-1,4-dioxaspiro[4.5]decan-8-ol (1.40 g, 3.95 mmol) was placed in a 50 ml round bottomed flask equipped with magnetic stirrer and Dean-Stark apparatus. Toluene (30 ml) was added, followed by camphor sulphonic acid (10 mg). The stirred solution was then heated under reflux for 1 hr, cooled and saturated aqueous sodium bicarbonate solution (10 ml) added. The mixture was poured into a separating funnel and the phases separated. The aqueous phase was extracted with ethyl acetate (2×15 ml) and the combined organics were washed with brine (15 ml), dried over anhydrous magnesium sulphate, filtered and then concentrated in vacuo yielding an orange oil which was purified by flash column chromatography (SiO2, ethyl acetate/petroleum ether, 45:55, v/v) to afford the title product (0.94 g) as a colourless oil. δH (CDCl3) 1.84 (2H, t), 2.41-2.43 (2H, m), 2.56-2.62 (2H, m), 3.47 (6H, s), 3.98-4.02 (4H, m), 5.13 (4H, s), 5.58-5.63 (1H, m), 6.64 (1H, dd), 6.78 (1H, d), 7.08 (1H, d).

1. customequipped with magnetic stirrer
2. temperatureThe stirred solution was then heated
3. temperatureunder reflux for 1 hr
4. temperaturecooled
5. additionThe mixture was poured into a separating funnel
6. customthe phases separated
7. extractionThe aqueous phase was extracted with ethyl acetate (2×15 ml)
8. washthe combined organics were washed with brine (15 ml)
9. dry with materialdried over anhydrous magnesium sulphate
10. filtrationfiltered
11. concentrationconcentrated in vacuo
12. customyielding an orange oil which
13. customwas purified by flash column chromatography (SiO2, ethyl acetate/petroleum ether, 45:55