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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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3
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1answer
351 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. ...
5
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2answers
3k views

Can substituted acetone undergo Cannizzaro reaction?

I know the Cannizzaro reaction takes place in carboxyl compounds without $\alpha$-H with the regular examples being formaldehyde and benzaldehyde. But can this reaction take place with say ...
0
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1answer
54 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, ...
4
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0answers
206 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 ...
4
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1answer
157 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 ...
3
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1answer
85 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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1answer
1k 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 ...
4
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1answer
305 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 ...
1
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1answer
751 views

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 ?
5
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1answer
456 views

Epoxide ring opening via decarboxylation

The answer for the above multiple choice problem is option (C), from which I can understand that at some point in the mechanism the molecule must've undergone decarboxylation. Also, I think the first ...
10
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1answer
255 views

Esterfication of 2,2,2-triphenylethanoic acid

Explain the formation of (1,1,1-triphenylmethyl)methyl ether when a solution of 2,2,2-triphenylethanoic acid in concentrated sulfuric acid is poured in methanol. I cannot figure out where is one ...
1
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1answer
55 views

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.
4
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1answer
1k views

Why is only bromine used in the degradation reaction?

Why specifically is bromine used in the degradation reaction (Hoffmann bromamide)? Why can't the same be performed using chlorine or iodine? In other words, what makes bromine a more convenient ...
9
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2answers
48k views

Why doesn't the Brady's test (2,4-DNPH) work on carboxylic acids?

Why does the Brady's test, the reaction of 2,4-dinitrophenylhydrazine with aldehydes and ketones, fail with carboxylic acids?
9
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1answer
1k views

In what way could benzoin give Tollen's test?

In Q29 of Joint Entrance Exam (JEE) 2016 India, the official answer key mentions that benzoin gives Tollen's test. However, I saw this post which says that it doesn't: Why do α-hydroxy ketones give ...
2
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1answer
89 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 ...
1
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1answer
111 views

What will be the product of this reaction?

We have an alpha beta unsaturated ether, along with a keto group in the same compound, which is being treated with a grignard reagent shown (assume the grignard reagent is in excess). Will it only ...
10
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4answers
633 views

With which group does the middle oxygen atom of an anhydride remain, on hydrolysis?

With which group does the middle oxygen atom of an anhydride remain, on hydrolysis? As an example, let us say we have the following modification of ethanoic methanoic anhydride, with the middle oxygen ...
1
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0answers
136 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)
1
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1answer
114 views

Methylnitrobenzene ring formation Synthetic Route

I know the malonic ester is probably used to make propanoic acid or some carboxylic acid, and then joined to the methylnitrobenzene. But I just can't figure out what glues to the methyl. I know the ...
3
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2answers
457 views

What is the mechanism for the oxidation of a lactol to a lactone?

Recently, I came to know that lactols can be converted to lactones but I wasn't able to find the suitable reagent and the reaction mechanism. Can someone elaborate the same?
10
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2answers
6k views

What are the products of the reaction of 1-methoxycyclohexene with dilute hydrochloric acid?

When 1-methoxycyclohexene is treated with dilute aqueous hydrochloric acid, methanol is produced along with another organic product. Identify this product. Explain why methoxycyclohexane is inert ...
0
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2answers
184 views

HCl/H2O with alkene: Which one reacts?

I think that the initial step forms a tertiary amine, which then in the presence of the ketone and trace acid undergoes nucleophilic addition. But then, for the $\ce{HCl/H2O}$ in the last step, which ...
0
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1answer
681 views

Why does Benzoin give positive Tollen's Test? [duplicate]

Certain alpha hydroxy ketones which can tautomerise to form an aldehyde will give a positive Tollen's Test. I was pretty clear with this idea until I came across this question and the answer given is ...
3
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2answers
2k views

Dehydration of carboxylic acids using P2O5

Why isn’t concentrated $\ce{H2SO4}$ used for the dehydration of carboxylic acids to anhydrides? What is special about $\ce{P2O5}$?
6
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1answer
577 views

Is this really a comparison of the absolute energies in the reaction energy profile for ester formation?

In Clayden et al., Organic Chemistry, p. 332, the authors compare the reaction energy profile for ester formation from a) acyl chloride and b) anhydride: They then write: The energy levels of the ...
9
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1answer
2k views

Mechanism of homologation of aldehyde to alkyne: Ohira–Bestmann reaction

This reaction was part of an organic scheme I was doing, and I was wondering what the mechanism of the reaction would be. I tried first forming a carbene by letting $\ce{N2}$ leave from the ...
9
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1answer
5k views

Why is benzoic acid a stronger acid than 3-aminobenzoic acid?

Why is benzoic acid a stronger acid than 3-aminobenzoic acid? Obviously at meta position, only negative inductive effect will operate. But, how does that make it a weaker acid than benzoic acid?
2
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2answers
492 views

Wavenumbers of cyclic ketones

Rank the compounds below in order of increasing C=O absorption frequency in IR spectrum (top - lowest wavenumber, bottom - highest wavenumber): Question: Would I count compound #1's cyclopentane or ...
8
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1answer
1k views

Racemization of ketones in presence of catalytic acid

Question: Which of the following ketones racemise in aqueous solution containing acidic or basic impurities? My answer: A and B should racemise in aqueous solution, for the carbonyl groups in A and B ...
2
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0answers
76 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
1k views

Chromic acid oxidation of aldehydes and primary alcohols

The answer has to be both A and D. Chromic acid is a strong oxidizer and will take both aldehydes and primary alcohols to carboxylic acids. However the computer thinks otherwise. Am I just missing ...
1
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1answer
655 views

Identify structure of compounds from their reactions and molecular formula

Compound P($\ce{C7H6O}$) on refluxing with aqueous ethanolic $\ce{KCN}$ solution for 1 hour, forms Q($\ce{C14H12O2}$). Q on oxidation gives R($\ce{C14H10O2}$). R on refluxing with aqueous $\ce{NaOH}$ ...
2
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1answer
495 views

Are PCC and Collin's reagent completely identical in their oxidizing action?

Are PCC and Collin's reagent completely identical in their oxidizing action? Is there any advantage (or disadvantages) over the other?
3
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1answer
472 views

Why do some nucleophiles attack at the carbonyl group while others at an alpha-carbon in ketones?

I was reading about the iodoform reaction and it stated that $\ce{OH^-}$ attacks at the $\alpha$-carbon and makes a substitution reaction possible. But there is also the possibility of attacking the ...
0
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1answer
46 views

What kind of mechanism is adopted here? [duplicate]

The relative reactivities of acyl compounds towards nucleophilic substitution is acyl chloride> anhydride>ester>amide. I would like to know how this kinetic property is decided. Is it on the basis of ...
9
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1answer
9k views

Why does LiAlH4 reduce an amide to an amine, but only reduce a ketone/aldehyde to an alcohol?

Here are two different reactions in which lithium aluminium hydride, $\ce{LiAlH4}$, reduces a carbonyl group: Why does $\ce{LiAlH4}$ completely remove the oxygen from the amide, but only reduces the ...
4
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3answers
4k views

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 ...
18
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2answers
873 views

Mechanism of a dephenylation reaction

I recently came across this reaction in my undergraduate labs. The experiment is taken from this article: J. Chem. Educ., 2008, 85, 413. The condensation of 2-methoxynaphthalene with cinnamoyl ...
4
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0answers
29 views

Could creating ashpalt roads actually be net CO2 reducing? [closed]

I remember reading a popsci book, which at some point mentioned, that the problem with reducing $\ce{CO_2}$ emissions was to actually trap carbon in long-term permanent structures. It then half-...
5
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1answer
2k views

Reaction mechanism of a terminal alkene with an anhydride

In a reaction (as given in my textbook), $$\ce{R-CH=CH2 + (CH3-CO)2O -> R-CH2=CH-COCH3}$$ an alkene reacts with acetic anhydride to give methyl alkenyl ketone. I am not sure of how this ...
11
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1answer
45k views

What is the mechanism for oxidation of ketones by the Popoff's rule?

Ketones are relatively much harder to oxidise, but they do undergo oxidation reactions at extreme temperatures. Our teacher also told us about Popoff's rule which states that, on oxidation of ...
7
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2answers
804 views

Why does formaldehyde exist primarily as the gem-diol in aqueous solution?

From Wikipedia, Methanediol is the product of the hydration of formaldehyde $\ce{H2C=O}$, and predominates in water solution: the equilibrium constant being about $10^3$ and in a 5% by weight ...
5
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1answer
2k views

Assignment of the IR spectrum of 2,4-pentanedione (acetylacetone)

The IR spectrum is shown here: My assignments so far: The 1728 and 1708 stretches correspond to $\ce{C=O}$ stretches in the keto form - the symmetric/asymmetric stretches respectively. The 3003 ...
3
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1answer
2k views

Carbonyl oxygen as nucleophile

Aldehydes and ketones have electrophilic centres at their carbonyl C, since the carbonyl O polarises the bond and attracts electron density towards itself on account of its high electronegativity. But ...
5
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3answers
386 views

Decarboxylation of cyclohex-1-ene-1,2-dicarboxylic acid by electrolysis method

What is the major product when cyclohex-1-ene-1,2-dicarboxylic acid is electrolysed? My try: I got 2 cases but I am unable to decide which product is major, and need help here.
2
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1answer
324 views

Omission of locants for functional groups in IUPAC names

I'm having a bit of conflict while naming molecules as per IUPAC the nomenclature rules. If we take the following compound for example, IUPAC would say that that correct name is 2-...
1
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1answer
208 views

Acid Catalysed Ring Expansion – Mechanism?

Ring expansion of vinyl cyclobutane - Could someone please help me with a detailed mechanism for the above conversion? It is the acid-catalyzed rearrangement of 4,7,7-trimethylbicyclo[3.2.0]hept-3-...
3
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0answers
47 views

Transformation of an epoxido-carboxylic acid to an aldehyde [duplicate]

So I am battling with the last part of this transformation and was hoping someone could explain this mechanism to me so that I can confirm my answer. Treating an alcohol with a strong hydrohalic ...
-1
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2answers
60 views

Addition of a methyl group to a heterobicyclic ring [closed]

I am battling to understand how this reaction works. It should be a carbonyl addition reaction but I am not 100% sure how to reach each step. Could someone explain the mechanism to me?