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.

Filter by
Sorted by
Tagged with
14
votes
2answers
7k views

Can an amide nitrogen be a hydrogen bond acceptor?

Can $\ce{N}$ (i.e. main chain $\ce{NH}$s of recognised residues in a peptide or protein) be a hydrogen bond acceptor? It is a well known fact that the main chain $\ce{NH}$s can be a hydrogen bond ...
1
vote
0answers
197 views

Mechanism of decarboxylation of cyclohexane-1,2-dicarboxylic acid

According to FIITJEE's Sankalp Test-II answer key, it was given that the following compound decarboxylates on heating: Then, I read Why are beta-ketoacids better at decarboxylation than gamma or ...
1
vote
0answers
35 views

Diketone intramolecular reaction question

I realize that one of the methyl groups on either carbonyl compound will become deprotonated and then it will attack the other carbonyl to form a pentane ring. However, with the methyl group in the ...
1
vote
0answers
30 views

Is the 1,4-adduct of carbonyl compounds ever a major product over the 1,2-adduct?

If, say, propenal undergoes nucleophilic addition of hydrazine, will the 1,2- adduct or the 1,4-adduct be preferred? Why? There is an obvious reasonace structure with an electrophilic beta carbon so ...
5
votes
1answer
147 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. ...
0
votes
0answers
33 views

Sources of carbon monoxide in dwellings

I am doing some research on indoor environmental quality and come across a number of spikes in CO in a dwelling. This is a dwelling in central London with no gas-fired equipment: electric cooker and ...
1
vote
0answers
65 views

Why do carbonyl groups lower antibonding orbital energies of conjugated systems?

In the chapter on conjugation in Organic Chemistry by Clayden, Greeves, Warren and Wothers, there's a brief discussion of pigments with conjugated systems that includes the following paragraph (first ...
4
votes
0answers
257 views

Does alcohol hydrogen in the enol tautomer of a β-dicarbonyl have sp² character?

My reasoning for the somewhat implausible "$\mathrm{sp^2}$" character of the hydrogen between these two oxygens on the enol structure of the right comes from recognizing that if it were, then we would ...
11
votes
2answers
3k views

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. ...
1
vote
0answers
160 views

Heating of cyclic dicarboxylic acid [closed]

How do we predict the products formed when we heat cyclic dicarboxylic acids? I know that in case of aliphatic dicarboxylic acids we apply Blanc's rule and predict the product formed based on the ...
5
votes
1answer
189 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, ...
4
votes
1answer
71 views

Are all fatty acids monocarboxylic acids?

The answer to this question might solve a multiple choice in my previous chemistry exam, which caused an argument with my teacher. We know that fatty acids form fats and oil due to their carboxylic ...
2
votes
2answers
836 views

How do α,β-unsaturated acids undergo decarboxylation?

I know the concerted mechanism for β-keto acids, but neither could I figure out, nor was I able to find out the mechanism for α,β-unsaturated acids. Any help is appreciated.
1
vote
0answers
92 views

Why are carbonyl groups so important [closed]

The most important are π orbitals as they are lower in energy than σ orbitals and the carbonyl group (C=O) is the most important of these—indeed it is the most important functional group of all. ~...
0
votes
0answers
126 views

Difference between base-promoted and base-catalysed

Why is halogenation of ketones in base described as being "base-promoted" and not "base-catalysed"? If the reaction is not "catalyzed" then how is the base used up?
2
votes
3answers
3k views

Why do carbonyl compounds undergo nucleophilic and not electrophilic addition?

Why aldehydes and ketones undergo nucleophilic addition reactions and not electrophilic addition? Alkenes show electrophilic addition because of pi bond, which is also present in aldehydes and ...
3
votes
1answer
130 views

Grignard alkene on a carbonyl

I was given the following mechanism to prove today post-lecture: and my attempt is given below. Now, when the negative charge on the alkene attacks the carbonyl, the electrons are pushed onto the ...
5
votes
2answers
897 views

Reaction of coumarin with phenylmagnesium bromide

I came across this problem.. I thought that the Grignard reagent, PhMgBr, would cleave the lactone and then subsequently add to the ketone formed, giving an allylic tertiary alcohol after aqueous ...
5
votes
3answers
450 views

What is the keto form of a hexahydroxybenzene?

159. The keto isomer of the following compound is: The answer has been given as (c). I cannot seem to understand why is it not possible for the keto form to only have one OH convert into keto ...
2
votes
0answers
812 views

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 ...
-3
votes
1answer
1k views

Why does aceto acetic ester not respond to haloform test even though it has a keto methyl group? [closed]

Why does aceto acetic ester not respond to haloform test even though it has a keto methyl group?
0
votes
0answers
62 views

Aldol Reaction in Water Not Working

I am conducting an Aldol formation reaction in water, and below is the experimental protocol I am following (from J. Org. Chem. 1994, 59, 3590—3596): Formation of Aldol in Water using Yb(OTf)3 ...
6
votes
2answers
1k views

Haloform reaction with limited bromine

We were asked the reaction between 1 mole acetone and 1 mole $\ce{Br2}$ in basic medium. Since only a limited amount of bromine was given I got the final answer as 1-bromopropan-2-one (mono bromo ...
7
votes
2answers
1k views

Mechanism of a cyclization reaction - why does an enol ether form?

I was asked to predict compound A from the follwing organic scheme: Looking at the formation of A, my prediction was that since TsOH is a strong acid, it would dehydrate the alcohols (like sulfuric ...
2
votes
2answers
2k views

Synthetic steps for the interconversion between aldehydes and ketones

I am learning about carbonyl chemistry at the moment. So far, we have been able to make aldehydes and ketones from alcohols (via oxidizing agents). I can't help but wonder if there is possibly any way ...
4
votes
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
12
votes
1answer
5k views

Why do alpha-hydroxy ketones respond positively to Tollens', Fehling's, Benedict's, Schiff's and HgCl2 tests?

I learnt from a certain textbook that aldehydes and formic acid respond positively to Tollens', Fehling's, Benedict's, Schiff's and HgCl2 tests. However, in another textbook I read that even alpha-...
4
votes
1answer
3k views

Best reagent for reducing a ketone in the presence of an alkene

The following reduction is best accomplished with: (a) Zn/Hg, conc. HCl (b) N2H4, C2H5ONa (c) H2, Pd (d) All of the above My thoughts: By looking at the question it is evident that ...
4
votes
0answers
106 views

Reagents for synthesis of ethyl 2-(2,3-dihydrobenzofuran-2-yl)acetate from naphthalen-1(4H)-one

The following conversion can be performed in a few steps. Show key intermediates and reagents (detailed mechanisms are not required). So I've been looking at this for a while and I can't seem ...
1
vote
0answers
432 views

Can 1,3,5-trihydroxybenzene perform haloform reaction?

As far as I know it's not possible for 1,3,5-trihydroxybenzene to give the haloform reaction. The prerequisites(that I know) for the haloform reaction are: Only those organic compounds which can be ...
0
votes
1answer
119 views

Why only ketone forms enolate in Claisen condensation between ester and ketone?

Claisen condensation involves nucleophilic substitution in esters by an enolate (formed by removing an alpha-H from an ester or a ketone) giving a beta-keto ester or a diketone. My textbook says ...
1
vote
1answer
1k 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 ...
-1
votes
1answer
993 views

Predict the major product of the following reaction with mechanism [closed]

I started to do the problem by coordinating H+ with the lone pair of oxygen then after that I can't proceed .please send the solution by show the detailed mechanism.
0
votes
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 ...
4
votes
0answers
64 views

An unconventional decarboxylation to form bullatenone

I recently had an assessment which required me to draw the mechanism of decarboxylation of a $\beta$-ketoacid. However, it is slightly peculiar because there is the presence of $\alpha$, $\beta$-...
1
vote
0answers
211 views

Reaction of Br2/KOH with succinic anhydride

What products will be formed when $\ce{Br2/KOH}$ reacts with the following compound in water at room temperature? Here is what I think is possible: $\ce{OH-}$ will take up the acidic hydrogen. ...
21
votes
4answers
6k views

Why do Organolithium or Grignard reagents act as nucleophiles and not as bases with aldehydes and ketones

I've read entire Chapter 14: Organometallic Compounds of Francis Carey's "Organic Chemistry" but I still didn't get an answer to my question. Quote from the book: Because of their basicity ...
-1
votes
1answer
97 views

What happens in this reaction! Some hints needed

I understand step A involves reductive ozonolysis. and that step B is addition involves addition of ammonia to the carbonyl site to form imines. But what does the sodium salt of trichloroacetic acid ...
2
votes
1answer
179 views

Why does the carbonyl of carboxylic acids get protonated and not the hydroxyl group?

Is the O of the C=O group more electronegative or is it for the sake of getting from product A to B that the carbonyl is protonated rather than the hydroxyl?
1
vote
0answers
83 views

Ring contraction in benzilic rearrangement

Wikipedia says that, Benzilic acid rearrangement occurs with ring contraction when used on cyclic diketones. But gave no explanation, can you please elaborate on this with some mechanism. One ...
2
votes
0answers
339 views

Ketal formation of ethyl acetoacetate

Why does the ketone carbonyl group react in preference to the ester carbonyl? Is it something to do with the resonance occurring into the ester carbonyl from the oxygen? but how does this make the ...
11
votes
4answers
3k views

Reasons for negative iodoform test

Why does 2',6'-dimethylacetophenone not give iodoform test?
0
votes
0answers
166 views

Mechanism for formation of amides from ammonium carboxylate salts

One of the reactions that you can do with a carboxylic acid is to react it with ammonia or an amine, which produces the corresponding ammonium carboxylate salt. When this salt is heated, amide is ...
1
vote
0answers
306 views

Why don't acyl chlorides give positive test with 2,4-DNPH?

In this post, Ron discusses the reasons why carboxylic acid derivatives such as amides, acids and esters do not give a positive result with 2,4-dinitrophenylhydrazine. He mentions that it is largely ...
1
vote
1answer
176 views

What reaction takes place here? [duplicate]

Upon reading the given question, I realized that: The first reaction is an aldol condensation reaction between the given compound and formaldehyde. So the product after 1st step is: Now, the ...
0
votes
1answer
163 views

Reaction of diacetyl with acid

What happens when diacetyl, that is, butan-2,3-dione is treated with acid? I guess there would be acid catalysed aldol formation. But what would the final product be? I can see too many ...
0
votes
1answer
181 views

Carbonation of Grignard reagent with a carbonyl group present in it

Here's the question in my book (see picture) Option A is a standard reaction which gives a carboxylic acid. Option B is definitely wrong because an acid base reaction will take place and CH4 will be ...
0
votes
0answers
37 views

How does chelation control result in rate acceleration?

In the chapter on diastereoselectivity in Clayden, Warren & Greeves (2012), the Cram-Chelate model is discussed. Most significantly, under chelation control, the diastereoselectivity of the ...
2
votes
1answer
333 views

Reduction with NH2-NH2 , OH-, and glycol

this question was asked in my exam and I have done it properly until the very third step but unfortunately, although the last step looked like wolfkishner reduction to me I could not do it. My ...
16
votes
1answer
1k views

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 ...

1 2
3
4 5
11