Ethyl 3-oxobutanoate (ethyl acetylacetate), can be obtained by Claisen from ethyl acetate, and is a very efficient reagent for the preparation of ketones.
![acetylacetic-synthesis sintesis-acetilacetica](/images/stories/organica-ii/compuestos-difuncionales/sintesis-acetilacetica/sintesis-acetilacetica-01.png)
Butanone [2] can be obtained from ethyl acetylacetate [1] through the indicated stages.
Stage 1. Formation of the ketoester enolate
![acetylacetic-synthesis sintesis-acetilacetica](/images/stories/organica-ii/compuestos-difuncionales/sintesis-acetilacetica/sintesis-acetilacetica-02.png)
Stage 2 . Nucleophilic attack of the ketoester enolate on the haloalkane.
![acetylacetic-synthesis sintesis-acetilacetica](/images/stories/organica-ii/compuestos-difuncionales/sintesis-acetilacetica/sintesis-acetilacetica-03.png)
Stage 3. Hydrolysis of the ester
![acetylacetic-synthesis sintesis-acetilacetica](/images/stories/organica-ii/compuestos-difuncionales/sintesis-acetilacetica/sintesis-acetilacetica-04.png)
Stage 4. Decarboxylation
![acetylacetic-synthesis sintesis-acetilacetica](/images/stories/organica-ii/compuestos-difuncionales/sintesis-acetilacetica/sintesis-acetilacetica-05.png)