反应详情

温度

-78 °C

A dry-ice-acetone cooled 500 mL-RB flask is charged with anhydrous THF (90 ml) and diisopropylamine (6.7 g, 0.066 mol). A solution of butyl lithium in hexanes (1.6 M, 48 ml, 0.075 mol) is added over 1 hour. After stirring at −78° C. for an additional 30 minutes, the mixture is warmed to 0° C. and stirred for an hour and at room temperature for 15 minutes. The mixture is cooled again in a dry-ice acetone bath, and anhydrous ethyl acetate (5.28 g, 0.06 mol) is added dropwise over 30 minutes. After the mixture is stirred at −78° C. for 1 hour, diisobutylsilanediyl bis(trifluoromethanesulfonate) (14.4 g, 0.01 mol) is added dropwise over 30 minutes. After about 4 hours, the reaction is quenched with water, and poured into ice-water. The organic layer is separated, and the aqueous layer is extracted with ether. The combined organic solution is washed with brine, dried over sodium sulfate, filtered, and the filtrate concentrated. The residue is purified by flash column chromatography on silica gel yield 2.6 g (27%) of product as a yellowish oil. 1H NMR (500 MHz, CDCl3, in ppm) δ 4.10 (q, 4H, J=7.0 Hz), 2.03 (s, 4H), 1.82-1.92 (theptat, 2H, J=6.5 Hz, 6.5 Hz), 1.25 (t, 6H, J=7.0 Hz), 0.96 (d, 12H, J=6.5 Hz), 0.75 (d, 4H, J=6.5 Hz).

1. temperaturethe mixture is warmed to 0° C.
2. stirringstirred for an hour and at room temperature for 15 minutes
3. temperatureThe mixture is cooled again in a dry-ice acetone bath
4. stirringAfter the mixture is stirred at −78° C. for 1 hour
5. waitAfter about 4 hours
6. customthe reaction is quenched with water
7. additionpoured into ice-water
8. customThe organic layer is separated
9. extractionthe aqueous layer is extracted with ether
10. washThe combined organic solution is washed with brine
11. dry with materialdried over sodium sulfate
12. filtrationfiltered
13. concentrationthe filtrate concentrated
14. customThe residue is purified by flash column chromatography on silica gel yield 2.6 g (27%) of product as a yellowish oil