Why does diethyl malonate undergo alkylation?
The a hydrogen atom of diethyl malonate is sufficiently acidic to be deprotonated by ethoxide ion. Subsequent alkylation with a primary or secondary alkyl halide yields an alkylated malonate ester. Acid catalyzed hydrolysis of the alkylated product yields a malonic acid that decarboxylates when heated.
What is Enolate alkylation?
The anions from ketones, called enolates, can act as a nucleophile in SN2 type reactions. Overall an α hydrogen is replaced with an alkyl group and a new carbon-carbon bond is formed. These alkylations are affected by the same limitations as SN2 reactions previously discussed.
What are the three steps in the malonate synthesis?
- The Common Pattern In The Malonic Ester Synthesis.
- Step 1: Deprotonation To Give An Enolate.
- Step 2: SN2 Reaction Of The Enolate Nucleophile With An Alkyl Halide Electrophile.
- Step 3: Acidic Ester Hydrolysis.
- Step 4: Decarboxylation To Give An Enol.
- Step 5: Tautomerization Of The Enol Back To The Carboxylic Acid.
How do you get rid of diethyl malonate?
The unreacted diethyl malonate was then removed by vacuum distillation to get the pure product as a colorless liquid.
How is diethyl malonate synthesized?
The malonic ester synthesis is a chemical reaction where diethyl malonate or another ester of malonic acid is alkylated at the carbon alpha (directly adjacent) to both carbonyl groups, and then converted to a substituted acetic acid.
How do you alkylate an enolate?
Enolates can be alkylated in the alpha position through an SN2 reaction with alkyl halides. During this reaction an α-hydrogen is replaced with an alkyl group and a new C-C bond is formed. The limitations of SN2 reactions still apply.
Is diethyl malonate toxic?
Background on Diethyl Malonate Table 1 below provides the CAS number, synonyms, and other information on diethyl malonate.
What is the chemical structure of diethyl malonate?
Diethyl malonate
| PubChem CID | 7761 |
|---|---|
| Structure | Find Similar Structures |
| Chemical Safety | Laboratory Chemical Safety Summary (LCSS) Datasheet |
| Molecular Formula | C7H12O4 |
| Synonyms | DIETHYL MALONATE 105-53-3 Diethyl propanedioate Ethyl malonate Malonic ester More… |
What is the role of malonate in this reaction?
The addition of malonate to the reaction mixture decreases the rate of the reaction. If more succinate is added, the reaction rate will increase.