Acetoacetic ester synthesis
Acetoacetic ester synthesis | |||||||||||
---|---|---|---|---|---|---|---|---|---|---|---|
Reaction type | Coupling reaction | ||||||||||
Reaction | |||||||||||
| |||||||||||
Conditions | |||||||||||
Temperature | +
| ||||||||||
Identifiers | |||||||||||
Organic Chemistry Portal | acetoacetic-ester-synthesis | ||||||||||
RSC ontology ID | RXNO:0000107 | ||||||||||
Acetoacetic ester synthesis is a chemical reaction where ethyl acetoacetate is alkylated at the
![Acetoacetic ester synthesis equation](https://upload.wikimedia.org/wikipedia/commons/thumb/e/e2/Acetoacetic_ester_synthesis_equation.svg/531px-Acetoacetic_ester_synthesis_equation.svg.png)
Mechanism[edit]
A strong base deprotonates the dicarbonyl
Double deprotonation of ethyl acetoacetate[edit]
The classical acetoacetatic ester synthesis utilizes the 1:1 conjugate base. Ethyl acetoacetate is however diprotic:[3]
- CH3C(O)CH2CO2Et + NaH → CH3C(O)CH(Na)CO2Et + H2
- CH3C(O)CH(Na)CO2Et + BuLi → LiCH2C(O)CH(Na)CO2Et + BuH
The dianion (i.e., LiCH2C(O)CH(Na)CO2Et) adds electrophile to the terminal carbon as depicted in the following simplified form:[3]
- LiCH2C(O)CH(Na)CO2Et + RX → RCH2C(O)CH(Na)CO2Et + LiX
See also[edit]
References[edit]
- ^ Smith, Janice Gorzynski. Organic Chemistry: Second Ed. 2008. pp 905–906
- ^ Acetoacetic Ester Synthesis – Alkylation of Enolates | PharmaXChange.info
- ^ a b Jin, Yinghua; Roberts, Frank G.; Coates, Robert M. (2007). "Stereoselective Isoprenoid Chain Extension with Acetoacetate Dianion: [(E, E, E)-Geranylgeraniol from (E, E)-Farnesol". Organic Syntheses. 84: 43. doi:10.15227/orgsyn.084.0043.