3-Methyl-2-buten-1-OL → 3-Methylbut-2-en-1-yl 3-oxobutanoate

Reaktionsgleichung

[CH3:1][C:2]([CH3:6])=[CH:3][CH2:4][OH:5].[CH2:7]=[C:8]1[O:12][C:10](=[O:11])[CH2:9]1>CCOCC.C([O-])(=O)C.[Na+]>[C:10]([O:5][CH2:4][CH:3]=[C:2]([CH3:6])[CH3:1])(=[O:11])[CH2:9][C:8]([CH3:7])=[O:12]

Komponenten

Versuchsvorschrift

A mixture of 3-methyl-2-buten-1-ol (21.2 g, 0.25 mole) and anhydrous sodium acetate (0.1 g) was cooled to 0°. Diketene (36 ml, 0.3 mole) was added dropwise over a period of 1.5 to 2 hours. The reaction mixture was then heated to 75°-80°, and this temperature was maintained for one hour. The mixture was diluted with ether. The ethereal solution was washed successively with aqueous 1N hydrochloric acid, saturated aqueous sodium bicarbonate, saturated aqueous sodium chloride, and then dried over magnesium sulfate. The ether was evaporated, leaving a residue which was distilled under vacuum, affording 3-methyl-2-butenyl acetoacetate (32.1 g, 76% yield); bp 114°-117°/18-19 mm.