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
1k views

How can this ketone show Cannizzaro reaction?

According to answer key, Cannizzaro reaction of 3-hydroxy-2,2-dimethyl-1-phenylpropan-1-one (a ketone) takes place but how is that possible when we know only aldehydes show Cannizzaro reaction?
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Is propane-1,2,3-tricarbaldehyde the correct IUPAC name of CHO-CH2-CH(CHO)-CH2-CHO?

We were asked this question in class: What is the IUPAC name of the compound $\ce{CHO-CH2-CH(CHO)-CH2-CHO}?$ I don't know for sure, but I think the answer should either be 3-formylpentan-1,5-dial ...
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353 views

Why do the amino groups in EDTA deprotonate first, in contrast to amino acids?

We know that in amino acids, carboxylic acid groups deprotonate first than the amine groups. For example, in alanine, $\mathrm{p}K_\mathrm{a,\ce{COOH}} = 2.34$, $\mathrm{p}K_\mathrm{a,\ce{NH3+}} = 9....
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On the mechanism of the nitrogen-removal step of the Wharton olefin synthesis

In today’s reaction seminar, the Wharton transposition made an appearance. In our practice case it started from the epoxide as in scheme 1 below as on Wikipedia; Kürti/Czakó (page 482) begin from the ...
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700 views

Reaction of hydrazine and hydroxylamines with carboxylic acids

Carboxylic acids and their derivatives on reaction with hydroxylamine $\ce{NH2OH}$ and hydrazine $\ce{N2H4}$ give hydroxamic acids and acid hydrazides, respectively, through acyl nucleophilic ...
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402 views

How do I arrive at the α-trimethylsilyloxy ketone from an unmodified ketone using TMSCl, triethylamine and mCPBA?

I'm confused about what is going on here. I gather that step 1 is typically supposed to protect an OH group, but there isn't any in the starting material.
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170 views

Intramolecular lactonisation in an unsaturated carboxylic acid

I am having some trouble figuring out how this reaction proceeds: Attempt 1: The most obvious thing to do is deprotonate the acid group. I tried using the carboxylate group to attack the alkene, ...
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789 views

Resonance of carbonyl

Carbonyl has two resonance structures, where the $\pi$-bond between C and O breaks and the electrons "move" to the oxygen atom. This gives an empty p-orbital in carbon and a p-orbital in oxygen with ...
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Mechanism for decarboxylation

Propose a mechanism for the following transformation. I gather that this mechanism might be similar to decarboxylation of keto acids: However, I am unsure of how to begin.
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Why is enol content higher in non-polar solvents?

Apparently, for keto-enol tautomerism, the enol content of a given carbonyl compound increases when in a non-polar solvent. What is the reason for this?
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Why don't Gringard Reagents react with carbonyls at the alpha position? [duplicate]

According to many texts, the reason why Gringard reagents cannot be used with alcohols is because the Gringard reagent is a strong base, which would deprotonate the alcohol. ($p\pu{K}_b$ of Gringard $\...
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Rearrangements of α-aminoketones in Clemmensen reduction

What is the possible mechanism for this reaction? Activated zinc in presence of concentrated hydrochloric acid is used for Clemmensen reduction, that is conversion of ketone group to methylene group. ...
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983 views

Sodium metal in acetone

When I place a chunk of 99,99% pure sodium metal in a beaker of (100% chemically pure) acetone, the sodium metal starts reacting and dissolving into the acetone and it forms a yellow/brown liquid. ...
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1answer
408 views

Why carboxylic group gets protonated preferantially on carbonyl oxygen?

When carboxylic group gets protonated, by strong acid, proton binds rather to carbonyl oxygen, then to hydroxyl. Is that really true? Or maybe it's a case of kinetic vs thermodynamic stability?
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Byproducts of LiAlH4 reduction of amides

I know that $\ce{LiAlH4}$ is able to reduce amides into amines, e.g. benzamide into benzylamine. However, I am unsure what other by-products are formed as a result. $$\ce{LiAlH4 + C6H5CONH2 -> ...
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Reactions of Grignard Reagents with amides

Can Grignard reagents add to amides? It appears from the synthetic pathway shown below that there has been some form of nucleophilic substitution at the carbonyl group. Source: 49th IChO Preparatory ...
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Why does the keto tautomer of guanine have lower energy?

Looking at the keto and enol forms of guanine, it would seem as if the enol form is more stable, due to the fact that aromaticity is established with the enol form. However, according to a question on ...
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1answer
356 views

Glycoside Formation Reaction

Whenever we add $\ce{H+}$/ Ethanol to glucose in its hemiacetal form, why doesn't pinacone/pinacolone rearrangement take place in place of nucleophillic substitution. The product would lead to ...
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Why can't Schiff's reagent distinguish between glucose and fructose?

I have heard that Schiff's base only gives a positive test for aldehydes. Glucose is an aldehyde. However, I was told that glucose doesn't give a positive Schiff's base test. Is this correct? If so, ...
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Why does the proton transfer from the oxygen to the nitrogen atom in imine formation not occur through an intramolecular process?

In my book Organic Chemistry by David Klein, 2nd edition, the book shows that the oxygen atom first takes a proton from an acid, then, the conjugate base of the acid takes a proton from the nitrogen ...
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317 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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What is the reason for colour in 2,4-Dinitrophenylhydrazine derivatives?

2,4-Dinitrophenylhydrazine is an important laboratory reagent for the detection of Carbonyl (C=O) group. It reacts with Carbonyl group by the typical Nucleophilic Addition-Elimination reaction and if ...
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Ease of reduction of carboxylic acid derivatives [duplicate]

Lithium aluminium hydride (LAH) is able to reduce aldehydes, ketones, carboxylic acids and esters. However, sodium borohyride ($\ce{NaBH4}$) is unable to reduce carboxylic acids and esters. Given that ...
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Single electron reduction of ketone by Na or Zn

Whenever we add Na or Zn metal to a ketone, why does the electron prefer to attack the carbonyl bond and form a radical, instead of removing the acidic hydrogen and forming an enolate and $\ce{H2}$ ...
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Decarboxylation of Salicylic acid

I would like to know how and under what conditions can decarboxylation of salicylic acid (o-hydroxybenzoic acid) occur. I couldn't find any sources for it online. Here are some reasons I think it ...
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1answer
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Ketone/aldehyde synthesis from N-acylazetidines or aziridines

A common principle in organic chemistry is to make sure the product is less reactive than the starting material, to prevent overreaction. So, for example, the treatment of an ester with a Grignard ...
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1answer
560 views

Mechanism of Hofmann Rearrangement Reaction

In the Hofmann Rearrangement Reaction (in basic medium), when $\ce{RNH-}$ ion is produced, why does it not attack $\ce{Br2}$ or take $\ce{H+}$from the amide itself? Also, why does it take $\ce{H+}$ ...
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1answer
86 views

What can be used to thionate a monosubstituted urea?

I'm looking to make a thiourea from a monosubstituted urea. I haven't found any references that use Lawesson's Reagent, which I have been using for the thionation of di and trisubstituted ureas. Is ...
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1answer
128 views

Is there a systematic naming system to name carbonyl derivatives?

I had asked a question earlier about how the “$\ce{-COOCl}$” functional group would be named. I had received a satisfactory answer that helped me completely understand how that compound was named. ...
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529 views

How would the “-COOCl” functional group be named?

I had this question that has been bouncing around for over 2 years. Basically, I imagined this molecule: This molecule, as far as my former (and current) knowledge of nomenclature goes, couldn't be ...
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433 views

Rate-determining step of Claisen condensation

If we use a strong base such as LDA or NaH, will the rate-determining step change from enolate ion formation to nucleophillic acyl substitution step?
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Mechanism of the reaction of cyclohexanone and nitric acid to form Adipic acid

Can I get some help in figuring out the mechanism for this reaction. Adipic acid is a molecule with two carboxylic groups,but I can't see how that happens. My initial thoughts involved that the ...
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1answer
328 views

Selectivity in acetonide formation from a polyol

In my total synthesis lecture notes the above example is given in which a polyol is reacted under acetonide forming conditions. The notes point out that this product is the only product, no other ...
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Why is nitrosobenzene electrophilic on O in organocatalytic oxygenations?

In 2003 Zhong1 and MacMillan2 reported the use of nitrosobenzene, PhNO, in the organocatalytic asymmetric α-oxygenation of carbonyl compounds: which is all nice, except for the slightly ...
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Sulfonyl azides: diazo or azide transfer?

Sulfonyl azides, $\ce{RSO2N3}$, are capable of acting as sources of electrophilic azide ("$\ce{N+3}$"), but are also capable of effecting diazo transfer, as shown in the scheme below, taken from ref 1:...
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Chelation-controlled aldol: why is the α substituent pseudo-axial?

In this Mukaiyama aldol reaction, taken from a 1999 paper by D.A. Evans,1 when $\ce{TiCl4}$ was used as the Lewis acid catalyst, the aldehyde 4a formed a chelated intermediate whereas 4b did not (due ...
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What's the reason for the instability of ethylene dione?

Ethylene dione, with a chemical formula $\ce{C2O2}$ and an IUPAC name of ethene-1,2-dione, is an oxocarbon. The Wikipedia page says: The existence of $\ce{OCCO}$ was first suggested in 1913. ...
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Decarboxylation mechanism and stability of α,β-unsaturated and α-hydroxy acids

I was wondering why α,β-unsaturated and α-hydroxy acids undergo decarboxylation. Also, I'm aware of neither the products nor mechanism. All I know is that β-keto acids and α-nitro compounds have ...
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Nucleophilic acyl substitution: conversion of butanoic acid to butanenitrile [closed]

How can I convert the carboxylic acid functional group into a nitrile?
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1answer
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Reduction of a ketone to an alkane

What is the mechanism for the reduction of ketone to alkanes using $\ce{H2}$, $\ce{Pd/C}$ in ethanol? Searching on Google mostly yields the reduction of ketones to secondary alcohols using LAH.
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1answer
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How to form an acetal from an enol ether?

I am having trouble understanding how the protecting group (ethylene glycol) is applied to the alkene next to the ether of highlighted step above. I thought maybe TsOH protonates the alkene as seen in ...
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1answer
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Why does the Rosenmund reduction stop at the aldehyde stage?

In the Rosenmund reduction, an acyl chloride can be reduced to an aldehyde by hydrogenation over a palladium catalyst poisoned with barium sulfate. Why isn't the aldehyde product further reduced to ...
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1answer
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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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1answer
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Does the oxidation for all the aliphatic monoaldehydes to carboxylic acids have the same value of electrode potential?

I have been wondering on this for quite a while. Consider aliphatic monoaldehydes. If I oxidize them, we get corresponding monocarboxylic acids. We can use certain oxidizing agents to perform the ...
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825 views

In the bicarbonate ion, why can the hydrogen not bond to the carbon?

I've been studying electrophiles and nucleophiles recently, including how the carbonate ion ($\ce{CO3^2-}$) is stabilised through resonance. While drawing the model for bicarbonate, however, I ...
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654 views

Why bond energy of acetone is more though it is more polar than formaldehyde?

I was going through the general properties of carbonyl compounds and then found this (in the pic) data, where it says that dipole moment of acetone (if we assume $\ce{R = -CH3}$) is more than ...
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3answers
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Is there intramolecular hydrogen bonding in salicylaldehyde?

Is there intramolecular hydrogen bonding between the hydroxyl and carbonyl groups? I think personally is that it does but what is concerning me is that I have got no adequate answer or response to my ...
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1answer
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Can hydrogen on platinum reduce carboxylic acids and esters?

Can $\ce{H2/Pt}$ reduce carboxylic acids and esters? I am confused about the reducing nature of hydrogen in presence of platinum. In some books, it reduces carboxylic acid and ester while in others, ...
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1answer
102 views

Reduction by hydrosilanes

I was trying to predict the following reaction as part of an organic reaction scheme: I thought that $\ce{Et3SiH}$ would reduce the ester to an aldehyde. But E turned out to be I see that the $\ce{-...
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1answer
599 views

What is the significance of the 2 and 4 positions in 2,4-DNP?

2,4-dinitrophenylhydrazine, a popular laboratory reagent is used to identify carbonyl compounds by forming 2,4-dinitrophenylhydrazones, which are often red or yellow colored precipitates. Why is the ...