Methyl vinyl ketone → 6,8-Dimethyl-3-Acetyl-2H-Chromene

反応式

[OH:1][C:2]1[C:9]([CH3:10])=[CH:8][C:7]([CH3:11])=[CH:6][C:3]=1[CH:4]=O.[O:12]=[C:13]([CH3:16])[CH:14]=[CH2:15].C(=O)([O-])[O-].[K+].[K+]>CC(=O)CC>[CH3:11][C:7]1[CH:6]=[C:3]2[C:2](=[C:9]([CH3:10])[CH:8]=1)[O:1][CH2:15][C:14]([C:13](=[O:12])[CH3:16])=[CH:4]2

参加物

実験手順

1.50 g (10 mmol) of 2-hydroxy-3,5-dimethylbenzaldehyde together with 0.66 g (10 mmol) of 3-oxo-1-butene are added at room temperature to a suspension of 0.14 g (1 mmol) of potassium carbonate in 50 ml of 2-butanone. The mixture is brought to reflux with stirring and this temperature is maintained for 90 minutes. The reaction medium is evaporated on a water bath under vacuum, and the residue is taken up with 100 ml of water and extracted 3 times with 75 ml of diethyl ether. The organic phases are combined, washed to neutrality with saturated aqueous sodium chloride solution, dried over sodium sulfate, filtered and evaporated on a water bath under vacuum, and chromatographed on a column of silica (70-230 mesh), eluting with dichloromethane.