Questions tagged [esters]
For questions about the synthesis, properties, and reactions of ester compounds, both organic and inorganic.
103
questions
4
votes
1answer
32 views
Mechanism of Acid Hydrolysis
I wanted to ask a question about acid catalysed hydrolysis.
I learnt in an introductory course to Physical Organic Chemistry that there are different ways that an ester can be hydrolysed acidically:
...
1
vote
0answers
34 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 ...
0
votes
2answers
35 views
Does this reaction require catalyst/solvent?
Planning on synthesising 2-formylphenyl benzoate by reacting benzoyl chloride with salicylaldehyde. Since both Benzoyl chloride and salicylaldehyde is liquid, will it require a catalyst/ solvent? Or ...
1
vote
1answer
105 views
Naming ester as a substituent to carboxylic acid
Can carboxylic acid functional group -COOH and ester's functional group R-COO-R' be in one structure? If yes, carboxylic acid will be the parent chain and ester will be the substituent as c.a. is ...
1
vote
1answer
195 views
Rate of hydrolysis of ester in presence of an acidic medium
Does the rate of hydrolysis of an ester depend on the concentration of both the ester and the acid, or only the ester?
I was told by my professor that hydrolysis of ester follows a pseudo-first order ...
1
vote
0answers
19 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 ...
1
vote
0answers
20 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 ...
1
vote
1answer
96 views
Thermal decomposition of ester [closed]
I have a clear liquid with a faint sweet smell. I know this compound contains an aromatic group and an ester. However, something strange happens when I try to distill it - it forms a white solid. I ...
-1
votes
1answer
56 views
Ester of glycerol and glyceric acid
What is the ester of glycerol ($\ce{C3H8O3}$) and glyceric acid ($\ce{C3H6O4}$)? I couldn't find any information about it online, so is this reaction even possible?
I'm not sure what would happen, ...
0
votes
0answers
38 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 ...
0
votes
1answer
91 views
Hybridization of carbon atoms present in the smallest ester?
I found this question in the Resonance DLPD Organic Chemistry book on Page 55:
What is the hybridization of carbon atoms present in the smallest ester?
The smallest ester as far as I know is ...
0
votes
1answer
74 views
Why doesn't self condensation occur in acetoacetic ester synthesis
So, I came across a quite versatile method to synthesize aldehydes and ketones, its called the Acetoacetic ester synthesis.
Suppose I need some 2-pentanone. So to synthesize it via this method I can ...
2
votes
1answer
72 views
Hydrolysis under basic medium
The first compound is said to be hydrolyzed more easily than the 2nd compound below under Alkaline medium . How is this possible ?
I thought due to resonance, -NO2 acquires negative charge which ...
3
votes
2answers
208 views
Are there amide versions of lactides and lactones?
In my book, I read that Lactides and lactones are cyclic esters which contain two and one ester group in them, respectively. They are formed when $\alpha$-hydroxy; and $\gamma$- or $\delta$- hydroxy ...
0
votes
0answers
69 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?
1
vote
1answer
52 views
Which are the radicals containing phosphorus in ATP?
The ATP molecule contains 3 $\ce P$ atoms linked through esteric bonds. The IUPAC name of triphosphate adenosine is "[[(2R,3S,4R,5R)-5-(6-aminopurin-9-yl)-3,4-dihydroxyoxolan-2-yl]methoxy-...
-3
votes
1answer
331 views
Vinyl vs Acryl IUPAC Usage [closed]
I have read that the word Vinyl and Acryl, both refer to the same group.
The difference is that Acryl is used for naming when the functional group attached itself contains a carbon atom while Vinyl ...
0
votes
1answer
45 views
Formation of (Gamma) Methylparaconic acid
I came across this question recently,
I tried to devise a mechanism but I'm struck here,
My try -
Moreover, I think my mechanism is somewhat inefficient because of formation of some byproducts, ...
0
votes
1answer
92 views
Acid hydrolysis of ethyl acetate [closed]
For my chemistry IA, I am planning to determine the reaction rate and activation energy of the acid catalyzed hydrolysis of ethyl acetate. Where can I find literature values for these, so i can ...
-1
votes
2answers
209 views
Fischer-Speier Esterification: Sulfuric acid removal following creation of ester
I'm a beginning chemistry student, and I was wondering what the best way of removing sulfuric acid was following the creation of benzyl acetate. So far, I have that benzyl alcohol and glacial acetic ...
3
votes
1answer
103 views
Mechanism for the intra-molecular exchange of an ester and a nitrile group
When the isolated product 4 is treated with sodium ethoxide in ethanol it rearranges to 5 as shown:
My TA says that you need to start with a reverse Claisen at the ketone but I am not quite ...
4
votes
2answers
178 views
Can the alkyl-oxygen bond in lactones be cleaved in an SN2 reaction?
I understand that nucleophiles typically attack the electrophilic carbonyl carbon of the lactone and open the ring through a nucleophilic acyl substitution. Has there ever been the case where the ...
1
vote
0answers
124 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)
1
vote
0answers
33 views
Confused about enolate chemistry [closed]
I'm not so sure how this mechanism is supposed to go. Could anyone provide some pointers?
The answer is supposed to be:
In particular, I'm confused about how to break up the two esters.
2
votes
0answers
67 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 ...
0
votes
1answer
174 views
Which mechanism is not seen during hydrolysis of esters? [closed]
Which mechanism is not seen during the hydrolysis of esters?
AAC2
BAC2
AAL2
BAL2
AAC1
I know that hydrolysis of ester is pseudo-first order reaction but I found this question where ...
2
votes
0answers
45 views
How do sulphate esters compare to phosphate esters? [closed]
In particular, the energy released from hydrolysis of the -S-O-S- bonds and how stable are they in aqueous solution compared to phosphate esters?
4
votes
1answer
264 views
Deciding more electrophilic centre between ester and thioester for SN type reaction
My question: (though it won't alter the product)
Which carbon is attacked first, the one adjacent to sulphur or the one adjacent to oxygen?
The solution says that the carbon adjacent to sulphur is ...
1
vote
1answer
607 views
Base used in Claisen Condensation
Here's what I read about which base to use in Claisen Condensation reaction (two esters or ester + carbonyl compound forming a beta keto-ester or beta-diketone):
The base used must not interfere ...
3
votes
1answer
708 views
What type of polyester is most commonly used for clothing?
Many polymers have the name of the monomer in their names, e.g. polyethylene, polyvinyl chloride, polypropylene, polystyrene etc. But the ester in polyester refers to a group of chemicals (having an ...
0
votes
1answer
57 views
Residual catalyst leaching from PETE
I am trying to look for healthy options for 5 gallon water jugs. The problem is all the plastic 5 gallon water jugs on the market are either made of #1 PETE (BPA free) or #7 (which contains BPA). It ...
5
votes
1answer
247 views
Can citric acid create a polyester?
Citric acid has both alcohol and carboxylic acid groups, so could it "esterify" with the other citric acid molecules in solution?
I notice that it is a tertiary alcohol. I don't suppose that would ...
2
votes
1answer
150 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 ...
2
votes
1answer
124 views
Does the slippery feeling of bases always appear at certain pH?
My guess is that the saponification reaction is only dependent on the concentration of $OH^{-1}$ ions and of course the coposition and concentration of fats. I also guess that the fat part of the ...
3
votes
1answer
557 views
Ethyl Acetate: how to store
I'm a 3D printing hobbyist and a few months ago I bought some Ethyl Acetate after learning online that it might have a similar effect on PLA as acetone has on ABS. From the tests I made, I was either ...
5
votes
1answer
11k views
Sulphuric Acid in Esterification Reaction
Why is it that adding the sulphuric acid slowly to a solution of alcohol and carboxylic acid (making an ester) will increase the yield of the product? It seems that not only does the rate at which it ...
1
vote
0answers
713 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" ...
4
votes
1answer
287 views
Hydrolysis of an ester
An organic compound X of formula $\ce{C5H10O2}$ forms two compounds when boiled in aqueous sodium hydroxide solution. One of these compounds forms a ketone when treated with acidified potassium ...
8
votes
2answers
769 views
Why are peroxides unstable but disulfide bridges considered stable? Why are esters stable but thiolesters are unstable?
I can not understand why a peroxide $\ce{R-O-O-R}$ is considered reactive and unstable.
Going down one row on the periodic table, a disulfide bridge ($\ce{R-S-S-R}$) is apparently super stable and ...
3
votes
0answers
451 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 ...
0
votes
2answers
718 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 ...
1
vote
0answers
690 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 ...
5
votes
1answer
2k 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 ...
0
votes
2answers
988 views
selective hydrolysis problem
I am aware that esters can be selectively hydrolysed depending on the type of alkyl group present e.g. Me ester vs t-butyl ester, the latter is reactive to acidic conditions and not basic because of ...
1
vote
0answers
489 views
Are esters and amides soluble in cold acids/bases? [closed]
The main problem I have is that we say amines are soluble in acids because they are bases, and they will thus react with acids. But if A reacts with B, how does that imply A is soluble in B? Yes, ...
1
vote
1answer
6k views
Is the reaction between a carboxylic acid and alcohol endothermic?
I would say that it is endothermic, and then by increasing the temperature, one could get more product, disturbing the equilibrium.
Is this true, though? During an esterification, some bonds are ...
2
votes
0answers
217 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?
4
votes
1answer
682 views
Which side of the C-o-C bond breaks in esters?
When an ester undergoes hydrolysis which side of the C-O-C breaks for instance in the following example:
I believe the first is correct but is it a rule that the salt of a carboxylic acid is formed (...
2
votes
1answer
726 views
Why do esters have to be distilled during purification?
I am currently designing a lab experiment for a school project in which I am to determine the effect of catalyst concentration ($\ce{H2SO4}$) on the rate of reaction between methanoic (formic) acid ...
1
vote
0answers
1k views
Direct conversion of amides to esters
Rarely does the literature describe the synthesis of esters from amides. I understand that amides are a relatively unreactive functional group but they can easily be hydrolysed to give carboxylic ...
