反应详情

A mixture of 4-hydroxyphenylpropan-2-one, ethylene ketal (3.88 g), 5-benzyloxy-2-chloromethyl-4H-pyran-4-one (5.0 g) and potassium carbonate 3.5 g) in acetone, was heated under reflux for 18 h. The reaction mixture was cooled, filtered and the solvent removed in vacuo. The residue was dissolved in ethyl acetate, washed with 2N-sodium hydroxide solution (1×50 ml), water (2×50 ml), dried (magnesium sulphate), filtered and evaporated to dryness in vacuo. The residue was purified by column chromatography on silica using chloroform as eluent, followed by crystallisation from acetone to give 2-(4-acetonylphenoxymethyl)-5-benzyloxy-4H-pyran-4-one ethylene ketal, (5.3 g).

1. temperaturewas heated
2. temperatureunder reflux for 18 h
3. temperatureThe reaction mixture was cooled
4. filtrationfiltered
5. customthe solvent removed in vacuo
6. dissolutionThe residue was dissolved in ethyl acetate
7. washwashed with 2N-sodium hydroxide solution (1×50 ml), water (2×50 ml)
8. dry with materialdried (magnesium sulphate)
9. filtrationfiltered
10. customevaporated to dryness in vacuo
11. customThe residue was purified by column chromatography on silica
12. customfollowed by crystallisation from acetone