Skip to main content
Library homepage
 

Text Color

Text Size

 

Margin Size

 

Font Type

Enable Dyslexic Font
Chemistry LibreTexts

Malonic Ester Synthesis

( \newcommand{\kernel}{\mathrm{null}\,}\)

Malonic ester synthesis is a synthetic procedure used to convert a compound that has the general structural formula 1 into a carboxylic acid that has the general structural formula 2.

malonicestersynthesis1.png

  • R1 = alkyl group
  • L = leaving group

The group —CH2CO2H in 2 is contributed by a malonic ester, hence the term malonic ester synthesis.

malonicestersynthesis2.png

  • R2 = alkyl, aryl

Malonic ester synthesis consists of four consecutive reactions that can be carried out in the same pot.

eg:

malonicestersynthesis3.png

reaction 1:

malonicestersynthesis4.png

reaction 2:

malonicestersynthesis5.png

reaction 3:

malonicestersynthesis6.png

reaction 4:

malonicestersynthesis7.png

A more direct method to convert 3 into 4 is the reaction of 3 with the enolate ion (5) of ethyl acetate followed by hydrolysis of the resultant ester.

malonicestersynthesis8.png

However, the generation of 5 from ethyl acetate 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.

malonicestersynthesis9.png

Malonic ester synthesis provides a more convenient alternative to convert 3 to 4. Malonic ester synthesis can be adapted to synthesize compounds that have the general structural formula 6.

malonicestersynthesis10.png

  • R3, R4 = identical or different alkyl groups

eg:

malonicestersynthesis11.png

reaction 1:

malonicestersynthesis12.png

reaction 2:

malonicestersynthesis13.png

reaction 1 (repeat):

malonicestersynthesis14.png

reaction 2 (repeat):

malonicestersynthesis15.png

reaction 3:

malonicestersynthesis16.png

reaction 4:

malonicestersynthesis17.png

see also acetoacetic ester synthesis


This page titled Malonic Ester Synthesis is shared under a All Rights Reserved (used with permission) license and was authored, remixed, and/or curated by Gamini Gunawardena via source content that was edited to the style and standards of the LibreTexts platform.

  • Was this article helpful?

Support Center

How can we help?