Reaktion #552618

Reaktionsgleichung

4-hydroxyphenylpropan-2-one

5-benzyloxy-2-chloromethyl-4H-pyran-4-one

potassium carbonate

acetone

→

2-(4-acetonylphenoxymethyl)-5-benzyloxy-4H-pyran-4-one ethylene ketal

Reaktionsbedingungen

Aufarbeitung

1. 1
   Temperaturwas heated
2. 2
   Temperaturunder reflux for 18 h
3. 3
   TemperaturThe reaction mixture was cooled
4. 4
   Filtrationfiltered
5. 5
   Sonstigethe solvent removed in vacuo
6. 6
   workup.DISSOLUTIONThe residue was dissolved in ethyl acetate
7. 7
   Waschenwashed with 2N-sodium hydroxide solution (1×50 ml), water (2×50 ml)
8. 8
   Trocknendried (magnesium sulphate)
9. 9
   Filtrationfiltered
10. 10
    Sonstigeevaporated to dryness in vacuo
11. 11
    SonstigeThe residue was purified by column chromatography on silica
12. 12
    Sonstigefollowed by crystallisation from acetone

Vorschrift

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).

Quelle