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

Reaction equation

[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]

Participants

Procedure

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 1 N 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.