Questions tagged [carbonyl-compounds]

For questions about compounds containing the carbonyl group, C=O, the carboxylic acid group (-COOH), or its derivatives (anhydrides/esters/amides/acid halides). For questions about complexes involving carbon monoxide as a ligand use [carbonyl-complexes] instead.

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1answer
277 views

Nucleophillic addition vs SN2

The following question came in Paper 2 of JEE Advanced 2014- Here we have $\ce{CH3-}$ as the nucleophile. There are 2 possible attacks: SN2 type attack on the chlorine group. Nucleophilic addition ...
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2answers
835 views

Less substituted vs more substituted alkene [closed]

In general, more substituted alkenes are more thermodynamically stable. However, in certain cases such as enamine alkylation, the less substituted double bond is favored. How do we know that which is ...
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Inductive vs conjugation effects in ester hydrolysis

I just came across the following problem about alkaline ester hydrolysis: Since all of the substituents are in the para position, I immediately thought about the ability of those substituents to ...
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1answer
2k views

Reaction between carboxylic acids and amines

Would some be able to explain why when I mix a carboxylic acid, like ethanoic acid, and an amine, say ethylamine, I get ethylammonium ethanoate. But when I mix a bi-functional group carboxylic acid (...
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1answer
1k views

Why are pi antibonding orbitals lower in energy than sigma antibonding orbitals?

I know when a carbonyl group is attacked by a nucleophile, the electrons of the nucleophile enter the antibonding π orbital of the $\ce{C=O}$ bond, which breaks the π bond. My textbook says that ...
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158 views

Kolbe's electrolysis of acetylenedicarboxylic acid

I have been wondering what this reaction would lead to? The ethyne diradical can't dimerize because triple bonded cyclic structures don't form until 8 carbons. And even if it polymerizes I find no way ...
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0answers
57 views

Regarding Clemensen Reduction of the following compound [duplicate]

While I was doing problems on reduction of aldehydes and ketones, I encountered this particular question Here, I know that Clemensen reduction reduces the ketone group to $-CH_2-$ group. But, the ...
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1answer
765 views

ICHO Synthesis Problem 2018

I've several doubts about this ICHO synthesis problem, which was a part of the preparatory problem package of 2018 (so yes, it's not a part of an ongoing contest) Before sharing the answer given, I'...
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1answer
495 views

Alcohol or Carbonyl - Which is more reactive towards PCl5?

We're aware that ketones and alcohols both react with phosphorus pentachloride, to produce geminal dichlorides and alkyl chlorides respectively. What happens in the compound shown below, when ...
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1answer
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How can benzaldehyde have a pKa of 14.9?

There are numerous websites out there which claim that the pKa of benzaldehyde – C6H5CHO – is 14.90. (Just do a Google search for benzaldehyde pka to see what I ...
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135 views

Why does gilman reagent react with acyl chlorides but not with other carbonyls?

According to HSAB (hard-soft acid-base) concept, a soft nucleophile preferentially reacts with soft electrophile and a hard nucleophile with a hard electrophile. Since $\ce {R2CuLi}$ is a soft ...
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1answer
131 views

Why can't you form an anhydride from an ester via nucleophilic attack?

The reaction referred to is the nucleophilic acyl substitution reaction, where the nucleophile is a carboxylate ion and the electrophile is the ester. I am having a difficult time visualizing why this ...
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1answer
866 views

Ketone prefix organic chemistry nomenclature

Is there a difference between the prefixes keto- and oxo-?
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1answer
523 views

Molecular orbital explanation of why the protonation of the oxygen atom makes a carbonyl group more electrophilic

I was working on nucleophilic addition reactions to the carbonyl group (namely, hemiacetal formation) when I came across the following explanation for the use of acid catalyst and how it increases ...
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0answers
154 views

What is a probable mechanism for acid catalysed decarboxylation of alpha-hydroxy acid?

The following question was on one of the tests we had recently Now i worked out the intermediates and the product as follows: The first step is an intramolecular Cannizzaro reaction in which the ...
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0answers
66 views

Are alkaline conditions required for Maillard reaction?

The Maillard reaction, a form of non-enzymatic browning, refers to a cascade of chemical reactions that frequently occurs in the cooking of foods (e.g. baking of pastries, roasting of meats). It ...
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1answer
810 views

Conditions for imine formation

Firstly, note that this is not a duplicate of Acid in Imine Formation. Clayden, Warren, & Greeves (2012) states explicitly on p. 231 that imine formation requires acid catalysis, and that the ...
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1answer
365 views

Which one is the stronger base?

I'm studying Wolff-Kishner reduction and I don't understand why after this step the leaving group is $\ce{OH-}$ instead of $\ce{^-HN-NH2}$. I guess it's because hydroxide ion is less strong than the ...
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1answer
149 views

How does this ring expansion on a steroid system occur?

The correct answer is supposedly B, as shown by Gravestock et al.[1] In this reaction after ozonolysis of the C=C double bond, two ketones are formed. How is a rearrangement or expansion of the ring ...
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1answer
200 views

Equation for the equilibrium constant for the hydration of carbonyls using UV spectroscopy

I was looking through the literature when I found a paper by Greenzaid et al. [1] which states that the equilibrium constant $K_\mathrm{hyd}$ is: $$K_\mathrm{hyd} = [\text{hydrate}]/[\text{carbonyl}...
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0answers
850 views

Effect of H-bonding on o-nitrobenzoic acid

My argument here is regarding the acidity of o-nitrobenzoic acid being greater than p,m-nitrobenzoic acid. In o-nitrobenzoic acid, there is an intramolecular hydrogen bond which makes the bond ...
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0answers
88 views

Claisen-like condensation with acid chloride

In the Claisen condensation, an ester enolate attacks an ester, with an alkoxide anion leaving subsequently to give a $\beta$-keto ester. Is it possible for a typical enolate of an aldehyde or ketone ...
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1answer
705 views

Why cyclohexane-1,4-dicarbaldehyde does not give aldol condensation?

I was recently came to know as a fact that cyclohexane-1,4-dicarbaldehyde does not give the aldol condensation reaction in spite of possessing α-hydrogens. I was told that this is due to steric ...
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1answer
311 views

Converting a thioester to an amide

What reagents can I use for the following transformation? I think this has something to do with formation of an iminium salt and reductive amination, but I'm not so sure.
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1answer
36 views

Will a reverse osmosis membrane exclude perfluorobutanoic acid?

I recently did a water quality test and it showed a detectable level of perfluorobutanoic acid, a potentially dangerous carboxylate PFC. Will a reverse osmosis water purification system exclude this ...
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1answer
392 views

What side reactions are suppressed by the use of TMSCl in the acyloin condensation?

I was reading about the acyloin condensation and came across a statemant according to which, the use of TMSCl obviates competing reactions. My question is what kind of competing reaction would happen ...
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1answer
376 views

Give the order of nucleophilic addition reaction in the following -

I am confused that whether we should take only inductive or hyperconjugation effect also into consideration while finding the order. As the answer in the book is only according to inductive effect . ...
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1answer
248 views

Do carboxylic acids form hydrates like aldehydes and ketones?

Having learned that aldehydes exist in equilibrium with their hydrate form - Do carboxylic acids do the same in a water solvent and form a hydrate with 3 $\ce{OH}$ groups and one alkyl group?
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1answer
514 views

Mechanism for conversion of imide to ester with NaH

What is the mechanism of this reaction? My proposed mechanism is shown below, would it work?
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2answers
1k views

Why does formic acid give positive Fehling's test?

$$\ce{HCOOH ->[\text{Fehling's solution}] CO2 + H2O}$$ The points discussed in a previous question do not account for the fact that formic acid also gives positive Fehling's test since it is not ...
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0answers
65 views

How would one disassociate the carboxylic acid on the end of a perfluorooctanoic acid molecule?

This is what a perfluorooctanoic acid molecule looks like. The carboxylate head on the end would normally disassociate in water because carboxylic acids are weak, but because of the fluorocarbon tail, ...
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1answer
80 views

Fluorination of Carbonyl Compounds using Molybdenum Hexafluoride

What is the mechanism of halogenation of carbonyl compounds using molybdenum hexafluoride? How does it work? Here's a reaction I came across: Can we use it for all carbonyl compounds? Are there ...
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1answer
249 views

Haloform Reaction of Furfural

My instructor pointed out that furfural undergoes haloform reaction - I don't understand how. I couldn't figure out the mechanism on my own, and couldn't find much online either. (regarding the ...
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1answer
240 views

Can enamines be formed from α,β-unsaturated ketones?

This question was a result of discussion form here: α,β-unsaturated carbonyl compounds and alkyl addition The reaction below (condensation of cyclohexenone with a secondary amine) does not yield any ...
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0answers
52 views

Why do amides react differently with PCl5? [duplicate]

In a reaction involving $\ce{PCl5}$ and any reactant containing oxygen atom, it generally takes out the oxygen and put chlorine their due to formation of strong bond between phosphorus and oxygen. ...
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1answer
924 views

What is the reaction of pentane-2,4-dione with chlorine in presence of NaOH? [duplicate]

We know that in haloform reaction alpha acidic hydrogen are substituted by halogen atom. But in the above case we find two acidic hydrogens in between the two keto groups (due to -R effect) which are ...
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0answers
53 views

Reactivity of carbonyl adjacent to cyclopropyl group

We know that cyclopropyl, because of $\ce{sp^{\sim 5}}$, hybrid orbitals behaves much like a double bond. It even takes part in conjugation to stabilise positive charge on carbons adjacent to it. I ...
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1answer
64 views

How far-reaching is the effect of conjugation?

Due to conjugation, it is possible for 1,4-addition, or conjugate addition, to occur. I was thinking, since conjugation and resonance effects do no diminish with distance, unlike inductive effects, ...
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1answer
232 views

Cyclisation reaction through hydrazine

The following reaction confuses me - I don't understand how and why it happened (couldn't figure out the mechanism): I thought this is some Wolff Kishner sort of reduction, but the reagents don't ...
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1answer
116 views

Conjugate addition vs Electrophilic addition

I was just doing an organic chemistry problem from an online source recently, on the topic of conjugate additions (or 1,4-additions). Below is an image illustrating the problem. I chose the upper ...
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0answers
257 views

Reaction of alpha hydroxyketone with KOH

What happens when 2-hydroxycyclohexan-1-one (an alpha hydroxyketone) reacts with aqueous $\ce{KOH}$? I tried something like Favorskii rearrangement, but it's wrong because OH isn't a good enough ...
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1answer
536 views

Malic acid 3-step synthesis

I was quite puzzled by the answer for this question in my Carboxylic Acids and Derivatives tutorial question set. It is question 6 (a), on the synthesis of malic acid, as shown in the image below. ...
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1answer
3k views

Why carbonyl groups are strong benzene deactivating group for electrophillic aromatic substitution?

In carbonyl group there is a resonance avaibility and also due to inductive effect it can also withdraw electron from benzene ring . As, resonance(e- donating chracter) dominates than Inductive effect ...
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1answer
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Reaction of 2,4-DNPH with aromatic aldehydes

Does 2,4-dinitrophenylhydrazine react with aromatic aldehydes, e.g. benzaldehyde (phenylmethanal), in a condensation reaction similar to 2,4-DNPH's reaction with aldehydes and ketones ?
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1answer
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Would this be a reasonable mechanism for the formation of a diazomethene?

I am mostly concerned about the first step. Are there any species in this mechanism that look too reactive for this mechanism to make sense? Any thoughts would be greatly appreciated.
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2answers
3k views

In Reimer-Tiemann reaction why does phenol attack the carbene from ortho position?

From the Wikipedia article on Reimer-Tiemann reation: In step 5, why doesn't the oxygen attack the carbene. The way I see it: upon attacking the carbene from ortho position, the mechanism ...
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How can I solve this synthesis?

I have this task to do: My solution: Is that possible? Can you please help me with the steps 2 and 3? This is what I did, but my teacher told me I should make the diketone (compound no. 5) from ...
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1answer
130 views

Origin of broad CO stretch in infrared spectrum of tricobalt cluster

I'm quite confident that the peaks around $\pu{2000 cm^{-1}}$ are $\ce{CO}$ stretches. But I cannot find any reference on that massive broad stretch following the $\ce{CO}$ stretches. Does it have ...
4
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2answers
953 views

If acyl chlorides are reacted with aqueous ammonia, will carboxylic acids also be formed?

As part of my A-level chemistry course, I have been taught that an acyl chloride will react violently with water to produce a carboxylic acid and hydrochloric acid. I have also been taught that an ...
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3answers
1k views

Reaction of NaOD/D2O with semicarbazone

I managed to solve the question till D but I'm stuck at the last reaction. I tried to find its solution and the source suggest it as

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