Questions tagged [esters]
For questions about the synthesis, properties, and reactions of ester compounds, both organic and inorganic.
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at what temperature does esterification occur without a catalyst?
I am investigating if the concentration of a reactant will increase the yield of an ester, (during an esterification process). But in order to see how much it was actually produced, I will need to ...
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21 views
Does this video show a correct process of esterification on banana oil? [closed]
https://youtu.be/sbvHiyHSGws
I dont understand. My professor said it was already wrong near the beginning of the video. Could someone explain to me the correct step by step process of this? :(
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Ester needed to replace Propylene Carbonate [duplicate]
I am looking for a clear ester to replace propylene carbonate that is not miscible in water, liquid at room temperature, safe to use for skin and hair and has a density of around 1.2 g/cm³?
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1answer
45 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 ...
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1answer
92 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 ...
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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 ...
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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 ...
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1answer
55 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 ...
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1answer
52 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, ...
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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 ...
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1answer
60 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 ...
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1answer
71 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 ...
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1answer
69 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
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2answers
201 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 ...
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0answers
62 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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1answer
45 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-...
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1answer
183 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 ...
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1answer
42 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, ...
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1answer
82 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 ...
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2answers
192 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
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1answer
94 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 ...
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2answers
172 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 ...
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0answers
117 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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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.
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0answers
61 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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1answer
139 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 ...
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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?
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1answer
225 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 ...
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1answer
579 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 ...
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1answer
589 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 ...
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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 ...
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1answer
236 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 ...
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1answer
148 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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1answer
119 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 ...
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1answer
489 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 ...
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1answer
10k 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 ...
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673 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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1answer
267 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 ...
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2answers
731 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 ...
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0answers
413 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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2answers
661 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 ...
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0answers
684 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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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 ...
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2answers
873 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 ...
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0answers
471 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, ...
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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 ...
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208 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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1answer
630 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 (...
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1answer
701 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 ...
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0answers
987 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 ...
