Questions tagged [esters]
For questions about the synthesis, properties, and reactions of ester compounds, both organic and inorganic.
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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 ...
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2answers
173 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
36 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
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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
45 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
36 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
46 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
68 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 ...
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1answer
82 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
130 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
81 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
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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
38 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
86 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
43 views
How to judge the polarity of the organic group?
I'm studying the esterification between ethylene glycol and different naphthenic acid model compounds, such as cyclohexylcarboxylic acid, cyclopentanoic acid，benzoic acid，etc., to apply for the ...
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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
112 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
348 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
347 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
55 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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0answers
172 views
How do I find activation energy of the esterification reaction between acetic acid and ethanol?
I am designing a lab on esterification with the purpose of find the activation energy of ethyl acetate. But all i could design is a procedure to find the rate of reaction. And I am confused after that....
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1answer
177 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
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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
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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
336 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
8k 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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0answers
512 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
215 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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204 views
Ester reduction with DIBAL — what is heat of reaction?
What is (or, where could I look up) a typical heat of reaction for an ester reduction with DIBAL? Such a reaction proceeds in two steps:
DIBAL reaction (exothermic):
Ester + DIBAL --> Unstable ...
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2answers
626 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
314 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
547 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
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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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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
563 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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348 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
4k 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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127 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
462 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
594 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
787 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 ...
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2answers
344 views
Retrosynthesis of a lactone
We have been asked to do a retrosynthesis of (6S)-6-[(2S)-2-hydroxy-4-phenylbutyl]oxan-2-one J from 3-phenylpropan-1-ol K:
My first instinct would be to do a functional group interconversion of the ...
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1answer
878 views
Finding the mystery ester strucuture using NMR
I have an unknown ester with the chemical formula $\ce{C9H10O2}$ that is used as a flavoring agent in candies. It exhibits the following H-NMR and C-NMR (Attached file: unknown ester NMR)
Based on ...
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2k 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
178 views
Why is the ester bond stable under Reformatsky reaction conditions?
The following reaction is a Reformatsky reaction.
Why is the ester bond not attacked in the last step? Couldn’t $\ce{OR3}$ be replaced by $\ce{OH}$ or $\ce{O(molecule)}$?
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1answer
284 views
Naming of ester alkoxide
I'm trying to name the following compound:
I believe the carboxyl group has priority and should make up the parent name. I'm not sure how to name the alcohol derivative portion. My first thought is:
...
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1answer
89 views
What is the major hydrolysis product of 2,2,2-trifluoroethyl 2-acetamido-3-phenylprop-2-enoate?
In the below reaction we have to find the major hydrolysis product of 2,2,2-trifluoroethyl 2-acetamido-3-phenylprop-2-enoate.
My doubt is why the major hydrolysis is not when $\ce{OH-}$ at the $\ce{C}...
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1answer
3k views
Will glycerol and citric acid react? If yes, under what conditions?
I would like to know whether the reaction will take place if glycerol and citric acid are merged? In particular, what will happen if both substances are heated up to high temperature (+100°C)?
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55 views
Why do esters smell more like fruit as their mass increases? [duplicate]
Is it all subjective or is there an actual reason?
Additionally, does the structure of an ester affect its smell? Are there any general trends with the type of smell and the type of ester?
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1answer
213 views
Which electronic effects are responsible for the reduction of nucleophilicity of a hydroxy group orthogonal to an ester?
I am facing a similar synthetic problem as Boekman Jr. et al noted in their synthesis of Tetronolide.[1] I will quote their’s rather than disclosing my actual synthetic problem, but note that the key ...
