Reacción #54964

Ecuación de reacción

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

Disolventes

ethanol

acetone

Condiciones de reacción

Tratamiento posterior

1. 1
   Otrofor a total of 48 hours
2. 2
   OtroThe catalyst was removed by filtration (`Hyflo` supercel) and the ethanol
3. 3
   Otroremoved in vacuo
4. 4
   Otroaffording an oil
5. 5
   OtroThe excess oxidant was destroyed with methanol
6. 6
   workup.DISSOLUTIONthe reaction mixture was dissolved in water (200 ml)
7. 7
   Extracciónextracted with ether
8. 8
   LavadoThe combined ethereal extracts were washed with water, dilute aqueous sodium bicarbonate solution and water
9. 9
   Secadodried (MgSO4)
10. 10
    Concentraciónconcentrated in vacuo

Procedimiento

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.

Fuente