反应详情

3.3 g of sodium hydroxide dissolved in 10 ml of water are added to a solution of 29.3 g of ethyl 3-(3-fluorophenyl)-3-(4-methanesulphonylphenyl)-2-(2-hydroxyethyl)-2-propenoate, prepared in Example 12, in 50 ml of ethanol and the mixture is refluxed for 2 hours. After evaporation to dryness, the residue is taken up with water, acidified with 1 N hydrochloric acid and then extracted with dichloromethane. The organic phase is dried over magnesium sulphate and evaporated under vacuum to give an oily residue. The oil is solubilized in 150 ml of toluene, and 10 mg of paratoluenesulphonic acid are added. The mixture is refluxed and the water formed is removed with a Dean-Stark apparatus. After cooling, the mixture is washed with water, the organic phase is dried over magnesium sulphate and evaporated under vacuum and the residue is chromatographed on silica in t-butyl methyl ether to give 4 g of (Z)-3-[1-(3-fluorophenyl)-1-(4-methanesulphonylphenyl)methylidene]dihydrofuran-2-one (2nd product eluted) in the form of crystals melting at 153-154° C.

1. temperaturethe mixture is refluxed for 2 hours
2. customAfter evaporation to dryness
3. extractionextracted with dichloromethane
4. dry with materialThe organic phase is dried over magnesium sulphate
5. customevaporated under vacuum
6. customto give an oily residue
7. temperatureThe mixture is refluxed
8. customis removed with a Dean-Stark apparatus
9. temperatureAfter cooling
10. washthe mixture is washed with water
11. dry with materialthe organic phase is dried over magnesium sulphate
12. customevaporated under vacuum
13. customthe residue is chromatographed on silica in t-butyl methyl ether