Reaktion #54964

Reaktionsgleichung

Methyl 2-[2-ethyl-3-methyl-4-oxo-4H-1-benzopyran-6-yl]propionate

Jones reagent

barium sulphate

→

title compound

Methyl 2-[2,3-dihydro-2-ethyl-3-methyl-4-oxo-4H-1-benzopyran-6-yl]propionate

Lösungsmittel

ethanol

acetone

Reaktionsbedingungen

Aufarbeitung

1. 1
   Sonstigefor a total of 48 hours
2. 2
   SonstigeThe catalyst was removed by filtration (`Hyflo` supercel) and the ethanol
3. 3
   Sonstigeremoved in vacuo
4. 4
   Sonstigeaffording an oil
5. 5
   SonstigeThe excess oxidant was destroyed with methanol
6. 6
   workup.DISSOLUTIONthe reaction mixture was dissolved in water (200 ml)
7. 7
   Extraktionextracted with ether
8. 8
   WaschenThe combined ethereal extracts were washed with water, dilute aqueous sodium bicarbonate solution and water
9. 9
   Trocknendried (MgSO4)
10. 10
    Einengenconcentrated in vacuo

Vorschrift

Methyl 2-[2-ethyl-3-methyl-4-oxo-4H-1-benzopyran-6-yl]propionate (6.61 g) was taken up in dry ethanol (150 ml) and hydrogenated at 85 p.s.i. with 5% palladium on carbon (0.2 g) and 5% palladium on barium sulphate (0.49) for a total of 48 hours. The catalyst was removed by filtration (`Hyflo` supercel) and the ethanol removed in vacuo affording an oil. The oil was taken up in acetone (50 ml) and treated with a slight excess of Jones reagent. The excess oxidant was destroyed with methanol and the reaction mixture was dissolved in water (200 ml) and extracted with ether. The combined ethereal extracts were washed with water, dilute aqueous sodium bicarbonate solution and water, dried (MgSO4) and concentrated in vacuo to give the title compound as an oil--6 g.

Quelle