Questions tagged [esters]

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

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What techniques can determine the concentration of ethyl acetate in a solution containing ethyl acetate, acetic acid, ethanol and water?

I need to monitor the concentration of ethyl acetate in an Fischer esterification reaction. What techniques or spectroscopies can detect the concentration of the compound? And which one do you ...
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1answer
4k views

Failed esterification of 1-butanol and ethanoic acid

I did an esterification experiment of 1-butanol and ethanoic acid. 30 mL of 1-butanol was added followed by 30 mL of ethanoic acid, and then 1.5 mL of concentrated sulphuric acid and some boiling ...
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2answers
7k views

Differentiating esters from glycosidic linkages

What exactly is the difference between an ester linkage and a glycosidic linkage? I know both release a molecule of water, but what is the difference? Is it simply which types of monomers are involved ...
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1answer
229 views

Why are the ethyl ester methylene protons not diastereotopic in ethyl (+-)-2-methylbutyrate?

In the following compound, there is one chiral center and two methylene groups. Why are the protons on the ethyl ester methylene not diastereotopic?
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0answers
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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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1answer
924 views

Why aqueous hydroxide is slippery (beyond just saponification)

A recent question mentions: Bases are soapy to touch because of soap formation on contact with lipids present on our skin. This is always the reasoning I hear, as well, and searching the internet ...
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1answer
699 views

Does the Dieckmann Reaction proceed via the conjugated enolate of the product?

In the following mechanism of the Dieckmann Condensation, the product has been formed in the fourth step, but still the reaction proceeds and $ \ce{RO^{-}}$deprotonates the product. Then $\ce{H^{+}}$ ...
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1answer
342 views

Naming of bicyclo[2.2.1]hept-5-ene-1,4,5,6-tetramethyl-3-bromo-2-ethyl carboxylate

I've synthesized a molecule (depicted above) using a Diels-Alder reaction, and I can't find it in any database (I used scifinder for my search), so I need advice about the name. The name I came up ...
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1answer
664 views

which starting material on heating with concentrated sulfuric acid generate cyclic ester

I have just learned esterification of normal reactions with aliphatic compounds, but this one is a cyclic compound. Is it different? There are both a hydroxyl group and a carboxyl group in choice B ...
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1answer
2k views

Alkaline Ester Hydrolysis Reaction

In an ester hydrolysis reaction using a dilute base what is the pH change before and after the reaction occurs. In this reaction I want to react methyl ethanoate with dilute sodium hydroxide. I want ...
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1answer
2k views

How can the formation of an alkene be explained during the hydrolysis of an ester when the alkoxy moiety is tertiary?

$$ \ce{RCOOR' + H2O -> RCOOH + R'OH} $$ But when $\ce{R'}=3^\circ$ it may result in the formation of alkene. But by the normal mechanism given in books and in various sites I am not able to explain ...
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How does this brominated intermediate lose its methyl group?

The problem is such: So far my working has been: I'm concerned about the last step where the ester forms a ring. The methyl group doesn't look like a plausible leaving group, but it does not ...
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1answer
195 views

Why does a carbonyl reform in ester reactions

I have noticed that frequently whenever esters react with a nucleophile, the nucleophile will attack the carbonyl carbon and eventually in order for the carbonyl to reform the other oxygen will leave ...
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2answers
1k views

Choice of base for malonic ester synthesis

Most reaction mechanisms use $\ce{EtO-}$ as a base to deprotonate the alpha hydrogen in the malonic ester sythesis. But in the equilibrium there are still esters that haven't been deprotonated. Why ...
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2answers
932 views

How to esterify phenol with oxalic acid?

Is it possible to fully esterify phenol with oxalic acid in order to get diphenyl oxalate? What catalyst should I use and is the synthesis possible to perform at home with hobby equipment?
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1answer
896 views

Mechanism for oxidative cleavage of tertiary alcohols by NaOCl

I came across this today An ester $\ce{C4H8O2}$ on reaction with $\ce{CH3MgCl} $ and hydrolysis gives an alcohol. The alcohol on reaction with $\ce{NaOCl}$ and $\ce{H3O+}$ gives acetic acid. ...
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2answers
3k views

Routes of formation of esters with highest yield

Esters can be formed in two ways according to the syllabus I'm following: (1) Mixing an alcohol with a carboxylic acid in the presence of sulfuric acid; and (2) Mixing an alcohol with an acid ...
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1answer
289 views

How can rotamers of alpha-keto esters be named to distinguish between different geometries?

When talking about free rotation it is often helpful to determine about which geometric arrangement one is referring to. For example in the case of butane we talk about several eclipsed or staggered ...
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1answer
122 views

How would I go about making an ethyl ester from vegetable oil?

I'm teaching myself how to make lotion and a lot of lotions contain esters like isopropyl myristate or isopropyl palmitate. I'd like to make an ethyl ester from a popular skin-care oil (olive, apricot ...
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1answer
13k views

What is the difference between the esterification and transesterification?

What is the difference between an esterification and a transesterification. Esterification objective is the formation of an ester by reacting an alcohol and a carboxylic acid. I am more concerned ...
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1answer
4k views

Protonation of ketone and ester

If there is a ketone and ester functional group in the same compound and I want to protonate with $\ce{HCl}$, which one will protonate first? Is it the carbonyl group in the ketone or the carbonyl ...
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1answer
788 views

Acid catalyzed hydrolysis of ester

During acid catalyzed hydrolysis of ester why does the carbonyl oxygen attack the $\ce{H^{+}}$ ? Why doesn't the alkoxy oxygen which is more electron rich and less electronegative not attack the $\ce{...
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1answer
5k views

Is it possible to oxidize ether to ester?

Is it possible to synthesize an ester from an ether in a single step? For example if I had an ether $\ce{(R-CH2-OR')}$, can I oxidize it so it will be an ester $\ce{(R-CO-OR')}$.
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1answer
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Mechanism for formation of amide by reaction of amine with ester

This is the mechanism given in my lecture handout: I have a problem with the third species along. Surely the negatively charged oxygen would protonate before the other oxygen would. Also, why does ...
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2answers
687 views

Why can you not make a compound with a quaternary alpha carbon using malonic ester?

So my textbook tells me that using a malonic ester to make a quaternary alpha carbon is impossible (I get that this might be hyperbole). However, it doesn't explain why and I don't understand why. ...
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1answer
252 views

Electrophilicities of carboxylic acid derivatives

I would like to ask about the rate of hydrolysis for 4-hydroxyphenyl acetate (A), N-(4-hydroxyphenyl)acetamide (B), 4-hydroxyphenyl chloroacetate (C), and methyl 4-hydroxybenzoate (D). I know that ...
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1answer
423 views

No chlorate esters? Why?

Why are there no chlorate esters? Or are they just undocumented or too unstable? I've seen perchlorate esters, but google "chlorate esters" and only perchlorate esters come up.
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Why do esters actually smell?

We all know the very famous esterification reaction, where a carboxylic acid and an alcohol react to give an ester and water. But why do they actually smell? What is the reason behind its aromatic ...
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1answer
705 views

Differences between alkyl halides and alkyl tosylates

What are the functional differences between alkyl halides alkyl tosylates? Both halides and tosylates are good leaving groups, yes. But is there chemistry that one will do and the other won't? Etc.? I'...
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1answer
5k views

Why are lactones more acidic than esters?

Lactones ($\mathrm pK_\mathrm a \sim 25$) tend to be more acidic than esters ($\mathrm pK_\mathrm a \sim 30$). I know that the lactone is fixed in a (E)-conformation, due to the ring: and that in ...
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1answer
362 views

Formation of methyl esters

Can't we perform Fischer esterification using methanol to make a methyl ester from a carboxylic acid? If so, why might we use diazomethane? Would the release of nitrogen gas confer an entropic ...
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2answers
8k views

Reaction of Grignard reagents with esters

Suppose I have a phenyl Grignard and methyl benzoate. If I react the two, can I expect benzophenone and a triphenylmethoxide ion as my products? I ask because I know that Grignards react with ...
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1answer
3k views

Are all esterification reactions reversible? What is their general mechanism?

For example the reaction of ethanoic acid with ethanol is reversible, however is this true for all esters? I'm not quite whether it is as easy for a reversible reaction to occur both ways. Is there a ...
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2answers
2k views

Oxidation numbers for esters?

How do I find the oxidation numbers for ester? My main issue is about finding the numbers for ester groups. /O\ - || R -- O -- C -- R' - I ...
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1answer
2k views

How many grams of each substance will be present at equilibrium in the reaction of ethanol and ethanoic acid?

In the following reaction, $K_c=4.0$: $$\ce{C2H5OH + CH3COOH <=> CH3COOC2H5 + H2O}$$ A reaction is allowed to occur in a mixture of $\pu{17.2 g}$ $\ce{C2H5OH}$, $\pu{23.8 g}$ $\ce{CH3COOH}...
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Resonance stability: ester vs. thioester

My problem set solution cites: "Although sulfur is less electronegative than oxygen, overlap is a more important consideration. Sulfur is a member of the third period. As a consequence, a ...
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During the development of aspartame, why was the methyl ester chosen?

One frequent argument against the safety of the synthetic sweetener aspartame is that it can be hydrolyzed, with one of the hydrolysis products being methanol, which is known to be toxic. Of course, ...

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