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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Because the question does not ask photosynthesis, I answer in the meaning of general chemistry: Light just provides energy for a reaction; usually, photons (the light particles) make electrons of the matter to excitate, thus changing the reaction conditions. Otherwise, in photosynthesis, light-dependent reactions produce a proton (H+) gradient flow through thylakoid membrane, thus spinning the ATPase enzyme subunits, thus producing ATP. Besides this, ferredoxin and NADPH is produced. Ferredoxin is very important for certain specific enzymatic reactions and NADPH is the carrier of reduction force (it can give a hydrogen to a chemical/metabolite, for example to malonic acid)
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.
Malonic acid is a competitive inhibitor of succinate dehydrogenase.
The hydrogen attached to a saturated carbon atom containing strong electron withdrawing groups in acidic form reacts with base to generate carbanion .such compounds which contain acidic CH2 group are called active methylene compounds . eg:CH3-CO-CH2-COO-C2H5 (ethyl aceto acetate
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.
Carbon Suboxide
it is a competitive inhibitor
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Yes, it is diprotic, HOOC-CH2-COOH
Yes it is because of it's 2 ends of hydroxide which is polar.
Caffeine can be synthesised (made artificially in a lab) by reacting dimethylurea with 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.
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