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Answered 2013-07-20 03:14:00

The Malonic Ester Synthesis begins with the dimethyl ester of a malonic acid (a beta-carboxy ester). This reaction is used to make substituted CARBOXYLIC ACIDS.

1. You start with malonic ester (a beta-carboxy ester) and alkylate it with an alkyl halide. This step is what attaches the alkyl group from the alkyl halide to the malonic ester at the position beta to both carbonyls.

2. You then add water and strong base to hydrolyze the ester groups at the ends into carboxylic acid groups, giving you malonic acid (a beta-diacid). It looks like the product from the first step, only there are carboxylic acids in place of the esters at both ends.

3. Upon gentle heating, a CO2 leaves giving the enol. The enol tautomerizes, meaning it introconverts into its isomer, the carboxylic acid. The carboxylic acid contains that R group that we attached during step 1.

The Acetoacetic Ester Synthesis has a different starting material, but follows the same Akylation-Hydrolysis-Decarboxylation steps! It is used to make asymmetrical, substituted KETONES.

1. You start with acetoacetate (a beta-keto ester) and alkylate it with an alkyl halide. This step is what attaches the alkyl group from the alkyl halide to acetoacetate at the position beta to both carbonyls.

2. You then add water and strong base to hydrolyze the ester group into a carboxylic acid, giving you a beta-keto acid. It looks like the product from the first step, only there's a carboxylic acid in place of the ester at the end.

3. Upon gentle heating, a CO2 leaves giving the enol. The enol tautomerizes, meaning it introconverts into its isomer, the ketone. The ketone is unsymmetrical due to that R group that we attached during step 1.

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Related Questions

What is reactive methylene compounds?

Such two compounds are Malonic ester and Acetoacetic ester.


What carboxylic acid would decarboxylate by heating?

A classic example of a carboxylic acid decarboxylation occurs in the 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. Malonic acid is another example of an acid that will decarboxylate when heated (not sure at what temperature this happens, though)The structure of malonic acid is HOOC-CH2-COOH.


Is malonic acid soluble in hexane?

No. Malonic acid is polar and hexane is nonpolar


What is malonic acid's role with respect to succinate dehydrogenase?

Malonic acid is a competitive inhibitor of succinate dehydrogenase.


How many protons can be lost by malonic acid?

Malonic acid has pKa values of 2.83 (pK1) and 5.69 (pK2). If malonic esters are used then on treatment with a strong base like sodium ethoxide, the methylene (-CH2-) hydrogen can be deprotonated, but I am not sure if that is possible for malonic acid as that will lead to a tri-anion.


Is malonic acid soluble in water?

Yes it is


What is the Emperical formula for malonic acid?

C3h4o4


Why Oxalic acid is stonger than malonic acid?

A strong acid has a stabilized conjugate base. Oxalic acid is stronger than malonic acid because its conjugate base has much more resonance structures than malonic acid's conjugate base.


What is the formula for malonic acid?

HOOC-CH2-COOH


What is the purpose of using malonic acid in this experiment?

it is a competitive inhibitor


When malonic acid is heated with P2O5 what is formed?

Carbon Suboxide


What is the chemical formula of malonic acid?

This formula is CH2(COOH)2.


A solution of malonic acid h2c3h2o4 was standardized by titration with 0.1000 M Naoh solution if 20.76 ml of the naoh solution were required to neutralize completely 13.15 ml of malonic acid solution?

.0899M


Is malonic acid a diprotic acid?

Yes, it is diprotic, HOOC-CH2-COOH


How is synthetic caffeine made?

Caffeine may be obtained from malonic acid and dimethylurea.


Is Malonic Acid polar?

Yes it is because of it's 2 ends of hydroxide which is polar.


Is malonic acid soluble in methanol?

yes, because it is polar. likes dissolves likes.


What reaction gives caffeine?

Caffeine can be synthesised (made artificially in a lab) by reacting dimethylurea with malonic acid.


In the Briggs Rauscher reaction can the Malonic acid be replaced by Oxalic acid?

In theory, any organic molecule with an enolic hydrogen (as in carboxylic acids, e.t.c.) can be used, it has simply been found that the malonic acid gives the most easily discernable colour changes and is just generally better for the reaction (Sorry for my lapse in scientific language there, I'm tired!). So the answer, in basics, is yes


Is the apple a acid or a base?

Yes, several weak acids in it. pH is about 3.5 to 4.5. There is even an acid named by them: malonic acid (propane-di-oic acid, C3H4O4).


What is the usage of diethyl malonate in organic synthesis?

Diethyl malonate, a colourless, fragrant liquid boiling at 199 C, is prepared by the reaction of monochloroacetatic acid with methanol, carbon monoxide or by the reaction cyanoacetic acid (the half nitriled-malonic acid) with ethyl alcohol. Diethyl malonate is an important intermediate in syntheses of vitamins B1 and B6, barbiturates, non-steroidal anti-inflammatory agents, other numerous pharmaceuticals, agrochemicals and flavors & fragrances compounds.


What acids are contained in soft drinks?

Pressured soft drinks contain at least carbonic acid (bubbling, about 0.5%). Depending on the flavor, citric acid (fruity) can also be added; malonic, tartaric and lactic acid are other examples sometimes used. Phosphoric acid is only allowed in (brown colored) coke.


Names of 20 acids?

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What are some seven letter words with 1st letter M and 2nd letter A and 4th letter O and 6th letter I?

According to SOWPODS (the combination of Scrabble dictionaries used around the world) there are 3 words with the pattern MA-O-I-. That is, seven letter words with 1st letter M and 2nd letter A and 4th letter O and 6th letter I. In alphabetical order, they are: mahonia malonic masonic


What are some seven letter words with 1st letter M and 2nd letter A and 3rd letter L and 7th letter C?

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