- Malonic ester synthesis
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. The major drawback of malonic ester synthesis is that the alkylation stage can also produce dialkylated structures. This makes separation of products difficult and yields lower.
A strong base is required to deprotonate the center proton. The protons alpha to carbonyl groups are easily deprotonated. The malonic ester is especially so by virtue of being adjacent to two carbonyl groups. The carbanion formed can undergo nucleophilic substitution on the alkyl halide, to give the alkylated compound. On heating, the di-ester undergoes thermal decarboxylation, yielding an acetic acid substituted by the appropriate R group. Thus, the malonic ester can be thought of being equivalent to the -CH2COOH synthon.
The ester may be dialkylated if deprotonation and alkylation are repeated before the addition of aqueous acid.
Cycloalkylcarboxylic acid synthesis
Intramolecular malonic ester synthesis occurs when reacted with a dihalide.. This reaction is also called the Perkin alicyclic synthesis (see: alicyclic compound) after investigator William Henry Perkin, Jr. 
- ^ House, Herbert O. (1972). Modern Synthetic Reactions. Menlo Park, CA.: W. A. Benjamin. ISBN 0-8053-4501-9.
- ^ Malonic Ester Synthesis - Alkylation of Enolates
- ^ "Malonic Ester Synthesis". Organic Chemistry Portal. http://www.organic-chemistry.org/namedreactions/malonic-ester-synthesis.shtm. Retrieved 2007-10-26.
- ^ Smith, Janice Gorzynski. Organic Chemistry: Second Ed. 2008. pp 905-906
- ^ Using the non-selective nature of malonic ester synthesis to produce cyclic compounds
- ^ Ueber die Einwirkung von Trimethylenbromid auf Acetessigäther, Benzoylessigäther und Malonsäureäther W. H. Perkin Jun. Berichte der deutschen chemischen Gesellschaft Volume 16 Issue 2, Pages 1787 - 1797 1883 doi:10.1002/cber.18830160259
Wikimedia Foundation. 2010.
Look at other dictionaries:
Acetoacetic ester synthesis — is a chemical reaction where ethyl acetoacetate is alkylated at the α carbon to both carbonyl groups and then converted into a ketone, or more specifically an α substituted acetone. This is very similar to malonic ester synthesis.:MechanismA… … Wikipedia
Malonic acid — Malonic acid … Wikipedia
Ester — For other uses, see Ester (disambiguation). A carboxylic acid ester. R and R denote any alkyl or aryl group, respectively Esters are chemical compounds derived by reacting an oxoacid with a hydroxyl compound such as an alcohol or phenol … Wikipedia
malonic acid — Chem. a white, crystalline, water soluble, dibasic acid, C3H4O4, easily decomposed by heat: used chiefly as an intermediate in the synthesis of barbiturates. [1885 90] * * * ▪ chemical compound also called Propanedioic Acid (HO2CCH2CO2H) … Universalium
malonic acid — məˈlōnik , länik noun Etymology: malonic from F. malonique (in acide malonique malonic acid), alteration of malique malic (in acide malique malic acid) more at malic acid : a crystalline dicarboxylic acid CH2(COOH)2 obtained by oxidation of malic … Useful english dictionary
malonic acid — A dicarboxylic acid of importance in intermediary metabolism; an inhibitor of succinate dehydrogenase. SYN: propanedioic acid. * * * ma·lo·nic acid mə lōn ik , län n a crystalline dicarboxylic acid CH2(COOH)2 used esp. in the form of its diethyl… … Medical dictionary
carboxylic acid — Chem. any organic acid containing one or more carboxyl groups. [1900 05; CARBOXYL + IC] * * * Any organic compound with the general chemical formula ―COOH in which a carbon (C) atom is bonded to an oxygen (O) atom by a double bond to make a… … Universalium
Diethyl malonate — Diethyl malonate … Wikipedia
Meldrum's acid — IUPAC name 2,2 Dimethyl 1,3 dioxane 4,6 dione … Wikipedia
Decarboxylation — is a chemical reaction that releases carbon dioxide (CO2). Usually, decarboxylation refers to a reaction of carboxylic acids, removing a carbon atom from a carbon chain. The reverse process, which is the first chemical step in photosynthesis, is… … Wikipedia