反应详情

温度

-78 °C

A round bottomed flask was loaded with 1-bromo-2,4-bis(methoxymethoxy)benzene (2.00 g) and THF (50 mL). N, N, N′, N′-Tetramethylethylene diamine (2.3 ml) was added and the solution was cooled to −78° C. n-Butyl lithium (9.5 ml, 1.6M in hexane) was added. The resulting solution was stirred for 1 hr at −78° C. and 1,4-cyclohexanedione monoethylene ketal (1.35 g) was added as a solution in THF (25 ml). The resulting solution was stirred at −78° C. for 1 hr and then allowed to warm to room temperature overnight. Hydrochloric acid (20 ml, 2M) was added and the reaction mixture stirred vigorously for 15 min. Ethyl acetate (100 ml) was added and the mixture poured into a separating funnel. The phases were separated and the aqueous phase was extracted with ethyl acetate (3×20 ml). The combined organic phases were washed with brine (20 ml), dried over anhydrous magnesium sulfate, filtered and concentrated affording an orange oil, which was purified by flash column chromatography (SiO2, ethyl acetate/petroleum ether, 45:55, v/v). The title product (1.42 g, 56%) was isolated as a colourless oil. m/z (ES+) 337 (M−H2O+H+); δH (CDCl3) 1.61-1.64(2H, m), 2.00-2.18(6H, m), 3.44(3H, s), 3.48(3H, s), 3.90-3.97(4H, m), 5.11(2H, s), 5.24(2H, s), 6.64(1H, dd), 6.82(1H, d), 7.20(1H, d).

1. additionwas added
2. stirringThe resulting solution was stirred at −78° C. for 1 hr
3. temperatureto warm to room temperature overnight
4. stirringthe reaction mixture stirred vigorously for 15 min
5. additionthe mixture poured into a separating funnel
6. customThe phases were separated
7. extractionthe aqueous phase was extracted with ethyl acetate (3×20 ml)
8. washThe combined organic phases were washed with brine (20 ml)
9. dry with materialdried over anhydrous magnesium sulfate
10. filtrationfiltered
11. concentrationconcentrated
12. customaffording an orange oil, which
13. customwas purified by flash column chromatography (SiO2, ethyl acetate/petroleum ether, 45:55