Questions tagged [esters]

For questions about the synthesis, properties, and reactions of ester compounds, both organic and inorganic.

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Interaction of trifluoroacetates with acetylcholinesterase

There exists a substance called TMTFA, or 3-(N,N,N-Trimethylammonio)-2,2,2-trifluoroacetophenone. It is known for being able to inhibit acetylcholinesterase at femtomolar concentrations. The TMTFA-...
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1answer
4k views

Protonation of Carbonyl oxygen in Fischer Esterification

In the Fischer Esterification, why is it the acid's carbonyl oxygen getting protonated and not the hydroxyl oxygen? This protonation occurs in Step 1 of the mechanism below. I read in some textbooks ...
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26 views

Preferred radical attack on a polyester

My question concerns the relative stability of a radical next to an ester oxygen compared to a radical next to an ester carbonyl carbon. The stabilizing effect of the electron pairs of ether oxygen ...
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89 views

How can I solubilize fragrance oil into polyvinyl acetate/clear glue?

I'm a high school student who makes slime for fun, using polyvinyl acetate (PVA) glue and borax as my main ingredients. Earlier, I had the idea of adding fragrance oils to clear glue. However, because ...
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840 views

Purification of polar NHS esters

What are the options that I might be missing for the purification of a molecule with the following characteristic: Contains an activated ester that reacts with water (NHS) Reacts readily with ...
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306 views

Hoffmann's rule in ester pyrolysis

Why is the Hoffmann's product the major product in the pyrolysis of an ester to form a carboxylic acid and alkene?
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55 views

Comparison: Esterification with acyl chloride and alcohol vs Fischer esterification

I would like to know if there are more than mentioned pros and cons with the different methods in making an ester, and also ways to maximize product yield (comparing the two). Fischer- Pros: cheap, ...
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70 views

Final product when sp2 oxygen of acid is O18 in fischer esterification

In the question above, i was curious about option 3. If the carbonyl oxygen is O18, shouldn't half of the product we obtain contain O18 on the carbonyl since we have two possible leaving groups with ...
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123 views

Can an enol acetate be formed through Fischer esterification?

Since acetone is converted into its enol form under acidic conditions, could it participate in Fischer esterification to form an enol acetate? For example, would refluxing acetone, p-TSA, and acetic ...
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3k views

Will oxalic acid react with ethanol?

Will oxalic acid, in a saturated solution in ethanol, be able to undergo an esterification reaction with the ethanol? This is assuming no acidifying agents (or anything else, for that matter) are ...
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1answer
271 views

Ester as a side product in the synthesis of bromoalkane from alcohol. Is it correct?

About 5 months ago, I answered a very interesting question albeit a very simple one. Why do we need sulfuric acid in creating alkyl bromide and not in creating alkyl iodide from alcohol and ...
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65 views

Why doesn't the acetic anhydride moeity react with the nucleophilic carbonyl oxygen of salicylic acid?

I know that salicylic acid with acetic anhydride under acidic conditions gives acetylsalicylic acid (aspirin). But my question is, why is it that post the protonation of carbonyl oxygen of acetic ...
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439 views

While treating 4-aminophenol with acetic anhydride why does the reaction stop at Paracetamol and does not undergo esterification with acetic acid?

This needs a little background so I will be showing you a question from one of my Organic Chemistry problem books:- Now, the book shows the answer as Option (c) which is Paracetamol. I tried to work ...
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39 views

Red Compound from Glycine and Glycerol?

I got an unexpected reaction which I'm trying to explain to myself: I mixed 10 parts glycerol with 1 part glycine at ~90C and to my great surprise the mixture turned from transparent to a tint of red. ...
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26 views

Pyridinium ion in inositol nicotinate

I have read about inositol nicotinate which is used as a medication for deficiency in vitamin B-3. I think that if acetic acid was applied to this medication it would form pyridinium ion and acetate ...
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87 views

Reduction of ester / eneone in presence of epoxide

I want to reduce an ester and an eneone in the presence of a terminal epoxide. I read on here @jerepierre did an ester in the presence of an epoxide with DIBAL. I know the DIBAL works for my ester, ...
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72 views

Does boric acid catalyze esterifications with isopropanol?

I am going to synthetise isopropyl salicylate. From what I have read on phillysim.org (pdf) the formation of ethyl salicylate can be catalyzed by boric acid. I could use sulfuric acid but it would be ...
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57 views

Using Wilkinson's Catalyst to reduce esters?

I was solving some questions on alcohols when I came upon a question in which it was asked that whether esters can be reduced using hydrogen in the prescence of wilkinson's catalyst. Now I know that ...
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176 views

What is first protonated aldehyde or lactone?

In a six membered lactone with carbaldehyde in beta position, which oxygen gets protonated first? the lactone or the aldehyde? (Using concentrated HCl)
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1k views

Esterification Colour Change

I was in a chemistry lecture about the upcoming laboratory practical on esters that I would have to take. My lecturer had mentioned that we ought not worry about "the pink coloration that will occur" ...
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741 views

Saponification value of a fat/oil

The saponification value of a fat was determined by adding $\pu{9.0 g}$ of the fat to flask containing $\pu{50.0 cm3}$ of $\pu{1.00 M}$ ethanolic potassium hydroxide. The remaining solution was ...
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105 views

Organic polyether with carboxyl moiety reacting with aldehyde, following reaction with sulfuric acid

I want to react the following molecule with conc. sulfuric acid in the presence of methanol at room temperature: If I am right, this would make a methyl ester to be formed on the carboxyl. The aim ...
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256 views

Why does adding PBS to a lipid+propylene glycol solution cause the lipid to precipitate?

I am trying to create an aqueous phospholipid suspension using ~50 mg of 1,2-dibehenoyl-sn-glycero-3-phosphocholine (DBPC), 13 mL of propylene glycol (PG), and 72 mL of phosphate-buffered saline (PBS)....
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49 views

Major product in the reaction of alcohol with unsymmetrical acid anhydride

When alcohol reacts with symmetrical acid anhydride to form ester. We have the following reaction, But if the acid anhydride used is unsymmetrical how can we identify the major product? For example ...
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246 views

Why ester reaction with one equivalent of Grignard reagent produces ketone?

While reviewing my old materials before an external exam which also covers these topic I stopped by one of the reactions - Grignard w/esters: From what I remember, and what my notes are also telling ...
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59 views

Reactions involving carboxylic acids

The following question was given in FIITJEE study material: I guess (i) step is de-esterification, which gives the compound of option (A). In next step, I wouldn't expect it to decarboxylate, instead ...
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247 views

Preparation of compounds using acetoacetic ester synthesis

I've been given the following exercise in organic chemistry, and I'm at a complete loss. The text book doesn't cover the subject at all. I have some knowledge of melonic ester synthesis. As an ...
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431 views

Why can't carboxylic acid + NaH + tert-butyl bromide react to create an ester?

So, the picture I showed above asks for which reagents can form the ester product. I was wondering why D can't form it? I was thinking that first, the $\ce{NaH}$ would react with the carboxylic acid ...
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50 views

Comparing acidity in 3,4-dihydroxyfuran-2(5H)-one and 2,3-dihydroxycyclopent-2-en-1-one

I have two compounds with two hydrogens namely (a),(b),(c) and (d). I have to compare the acidity of the following hydrogens. My approach: I removed the hydrogen atoms one by one and compared the ...
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207 views

Why mixture turns brown upon heating, during esterification with H2SO4?

In the lab I was synthesising an ester with sulphuric acid as a catalyst. However the mixture turned brown and my teacher said I had burnt the acid, but what does this actually mean?
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2answers
2k views

Esterification with tertiary alcohol

I saw a different mechanism for esterification of tertiary alcohol in a book. They say that first the $\ce{OH}$ is protonated and it leaves to form the tertiary carbocation. Then the oxygen's lone ...