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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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1answer
357 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 ...
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1answer
261 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.
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1answer
211 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
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0answers
56 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 $\alpha$, $\beta$-...
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0answers
84 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. ...
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0answers
54 views

Rate of nucleophilic addition reaction of carbonyl compounds

How should I compare the order of rate of 1.formaldehyde 2.ethanal 3.p-nitrobenzaldehyde 4.p-methoxybenzaldehyde For nucleophilic addition the rate depends on the intensity of electron deficiency of ...
21
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4answers
5k 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 ...
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1answer
64 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
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1answer
67 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?
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0answers
47 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
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0answers
276 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
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4answers
2k views

Reasons for negative iodoform test

Why does 2',6'-dimethylacetophenone not give iodoform test?
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0answers
86 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 ...
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0answers
162 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 ...
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1answer
111 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 ...
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1answer
90 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
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1answer
86 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
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0answers
33 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 ...
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0answers
24 views

Reactivity of formaldehyde and 2-chloroethanal towards nucleophillic addition

Formaldehyde is sterically less hindered than 2-chloroethanal and inductiv effects also support a greater reactivity of formaldehyde over the later. However my textbook states that the reactivity ...
2
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1answer
137 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 ...
14
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2answers
725 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
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1answer
250 views

Mechanism with hypohalite in haloform reaction

The haloform reaction is usually done in a solution of NaOH and $\ce{I2}$ (or indeed, any halogen). Now the first part of the reaction mechanism in the wikipedia page and in the most organic books ...
2
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0answers
70 views

The use of silyl enol ethers over aza-enolates

I do not quite understand how alkylations using tertiary halides would work better with silyl enol ethers, compared with using the aza-enolate nucleophile. The following was mentioned in Clayden, ...
2
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1answer
2k views

Is butanoic acid more soluble in water than ethyl acetate?

I was asked which of the two following isomeric compounds, a carboxylic acid and an ester, was more soluble in water. I believe both molecules should be somewhat soluble in water as they have polar C=...
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1answer
66 views

Preference for basic conditions in ester hydrolysis

It has occurred to me that it is very common see the use of basic conditions for ester hydrolysis in various syntheses. One such sequence commonly seen in the case of the malonic ester synthesis is: $...
6
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2answers
12k views

Does Br2/H2O oxidize all aldehydes?

In many books, it is mentioned that aldehydes are easily oxidized even by mild oxidizing agents. However, I have never seen bromine water explicitly mentioned. But in the carbohydrates chapter, it is ...
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1answer
126 views

Oxalate Anion MO Diagram

I figured I’d study $\ce{C2O4^2-}$ as an organometallic ligand, and found that it is weak field (pi donor). I hence decided to construct a MO diagram. The oxalate anion is of D2h symmetry, so one ...
3
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0answers
95 views

How can the ketone in a β-ketoester be protected during hydride reduction?

I am supposed to find what X is. I know that $\ce{LiAlH_4}$ will convert all carbonyl groups to alcohols, and the ester group is being reduced. The only way of ending up with a ketone that I can think ...
4
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0answers
690 views

Predicting IR frequencies of esters / vinylogous esters

Here's the problem... Three isomeric structures with formula $\ce{C10H8O2}$ are shown: Identify the correct ordering of carbonyl IR stretching frequencies. I understand that conjugation ...
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1answer
45 views

Reagents in Krapcho's decarboxylation

Krapcho's decarboxylation is a reaction involving esters with a electron-withdrawing group $\beta$ to the carbonyl group and halide ions. It is typically conducted with $\ce {LiCl}$ and $\ce {DMSO}$ ...
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0answers
39 views

What takes place in this transformation of the 1,3-dicarbonyl?

I was just looking at a particular synthesis method on the Organic Chemistry Portal when I saw a particularly puzzling step, involving a 1,3-dicarbonyl compound. The step which I am puzzled by is ...
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0answers
33 views

Cross Cannizzarro reaction for ketones

I want to ask that cross cannizzarro could be possible between any aldehyde + ketone mixture(without alpha H) and we get products as aldehyde get oxidised and ketone get reduced(along with self ...
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1answer
143 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
257 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 ...
3
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1answer
477 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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1answer
767 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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0answers
127 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 ...
8
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1answer
936 views

Naming compounds with multiple -COX functional groups

I know that this compound is named propanoyl chloride. However I am not sure what to do when here are multiple -COX groups and they are of the highest seniority. There are two cases, when they are ...
1
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0answers
39 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 ...
2
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0answers
50 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
681 views

Reagents to synthesise butanedioic acid from 1,2-dibromoethane

Why can't we use $\ce{HCN (g)}$ and $\ce{HCl (aq)}$ to convert 1,2-dibromoethane into butanedioic acid? I found out that the answer is $\ce{KCN (aq/alcoholic)}$ and $\ce{H2SO4 (aq)}$, I don't ...
3
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1answer
12k views

aldehydes are easily oxidised but ketones are not

Aldehydes are easily oxidized to carboxylic acid but ketones are difficult to oxidise. Most books say that the hydrogen directly bonded to the $\ce{C=O}$ in the aldehyde is what aids the oxidation ...
6
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1answer
983 views

Mechanism for conversion of ketone to dichloride with phosphorus pentachloride

I would like to know the mechanism of this reaction leading to the formation of a geminal dichloride. I am unable to predict how the $\ce{C=O}$ breaks and how the 2 $\ce{Cl}$ atoms replace the oxygen ...
15
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1answer
567 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'...
8
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1answer
228 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
140 views

What is the final product of a carbohydrate treated successively with hydrogen cyanide, water, and hydrogen iodide/ phosphorus?

An unknown carbohydrate is successively treated with (1) hydrogen cyanide, (2) water, and (3) hydrogen iodide and phosphorus: $$\ce{C6H12O6 ->[HCN] X ->[H2O] Y ->[HI,P]Z}$$ What is the ...
7
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2answers
9k views

How can an α,β-unsaturated ketone tautomerise?

I was taught that for aldehydes and ketone to exhibit keto-enol tautomerism, it is essential that there must be at least one α-hydrogen. For example, acetophenone and butan-2-one show keto-enol ...
2
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3answers
396 views

Alkali metal enolates

Why do lithium enolates add to an electrophile in direct addition manner, while the sodium and potassium enolates tend to add in conjugated additions? The sodium and potassium enolates are well ...
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1answer
76 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 ...
2
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0answers
86 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 ...