Acetoacetic ester synthesis is a synthetic procedure used to convert a compound that has the general structural formula 1 into aketone that has the general structural formula 2.
- R1 = alvikyl
- L = leang group
The group —CH2COCH3 in 2 is contributed by an acetoacetic ester, hence the term acetoacetic ester synthesis.
- R2 = alkyl, aryl
Acetoacetic ester synthesis consists of four consecutive reactions that can be carried out in the same pot.
- reaction 1: acid-base reaction
- reaction 2: nucleophilic substitution
- reaction 3: ester hydrolysis (using saponification)
- reaction 4: decarboxylation
A more direct method to convert 3 to 4 is the reaction of 3 with the enolate ion (5) of acetone.
However, the generation of 5 from acetone quantitatively in high yield is not an easy task because the reaction requires a very strong base, such as LDA, and must be carried out at very low temperature under strictly anhydrous conditions.
Acetoacetic ester synthesis provides a more convenient alternative to convert 3 to 4.
Acetoacetic ester synthesis can be adapted to synthesize compounds that have the general structural formula 6.
R3, R4 = identical or different alkyl groups
reaction 1 (repeat):
reaction 2 (repeat):