反应详情

In this Example, 45 g of (3-dimethylaminopropyl)triphenylphosphonium bromide hydrobromide is suspended in 200 ml of tetrahydrofuran under a nitrogen atmosphere and 82 ml of 1.6N-n-butyl lithium hexane solution is added thereto under ice-cooling. The mixture is stirred under ice-cooling for one hour. To the mixture is dropwise added under ice-cooling a solution obtained by dissolving 10 g of methyl 11-oxo-6,11-dihydrodibenz[b,e]oxepin-2-carboxylate in 200 ml of tetrahydrofuran. After stirring the mixture at room temperature for 2 hours, the mixture is extracted with 800 ml of ethyl acetate. After washing the extract with saturated aqueous sodium chloride solution and drying the extract over anhydrous sodium sulfate, the solvent is distilled away under reduced pressure. The residue is purified by column chromatography on silica gel (eluent: hexane:ethyl acetate:triethylamine=10:10:1) to obtain 2.0 g of trans form and 5.6 g of cis form of the desired product.

1. temperatureunder ice-cooling
2. temperaturecooling for one hour
3. additionTo the mixture is dropwise added under ice-
4. temperaturecooling a solution
5. customobtained
6. stirringAfter stirring the mixture at room temperature for 2 hours
7. extractionthe mixture is extracted with 800 ml of ethyl acetate
8. washAfter washing the
9. extractionextract with saturated aqueous sodium chloride solution
10. customdrying the
11. extractionextract over anhydrous sodium sulfate
12. distillationthe solvent is distilled away under reduced pressure
13. customThe residue is purified by column chromatography on silica gel (eluent: hexane:ethyl acetate:triethylamine=10:10:1)