反应详情

3.17 g (10.14 mmol) of 1-allyl 7-ethyl 2-allyloxycarbonylheptanedioate (Example 48A) are dissolved in 30 ml of DMF and, at 0° C., 0.45 g (11.15 mmol) of 60% sodium hydride is added in portions, and the mixture is stirred at RT for 30 minutes. After renewed cooling to 0° C., a solution of 5 g (13.18 mmol) of 3,5-difluoro-4-triisopropylsilanyloxybenzyl bromide in 20 ml of DMF is added dropwise, and the mixture is stirred while warming to room temperature overnight. The mixture is poured into ice, weakly acidified with hydrochloric acid and extracted with ethyl acetate. The combined organic phases are dried over sodium sulfate and concentrated. The resulting crude product is purified by chromatography on silica gel (mobile phase: cyclohexane, then cyclohexane/ethyl acetate 10:1). 4.57 g (73% of theory) of the title compound are obtained.

1. temperatureAfter renewed cooling to 0° C.
2. stirringthe mixture is stirred
3. temperaturewhile warming to room temperature overnight
4. additionThe mixture is poured into ice
5. extractionextracted with ethyl acetate
6. dry with materialThe combined organic phases are dried over sodium sulfate
7. concentrationconcentrated
8. customThe resulting crude product is purified by chromatography on silica gel (mobile phase