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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7
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1answer
2k views

Does aldol condensation give different products in different conditions?

I know the mechanism of aldol condensation and general method to determine products in crossed aldol reactions, or reactions between dissimilar molecules. But the following statement in my class notes ...
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1answer
847 views

Does the iodoform reaction form hydrogen iodide or water?

I am currently learning about the iodoform reaction, i.e. when CH3COR compounds react with iodine and sodium hydroxide to form iodoform. My course book and Chemguide both says that the reaction is as ...
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1answer
82 views

Same set of carboxylate reagents yielding two different products with an alkylide

I recently came across two contrasting products for the same set of reagents - carboxylic acid and alkyllithium, and wish to understand why exactly any difference exists between the two. Reaction 1 ...
6
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1answer
2k views

Are groups other than carbonyl reduced by Clemmensen reduction?

According to my textbook, Clemmensen reduction reduces only aldehydes and ketones to alkanes. But in this question: $\ce{Zn-Hg/HCl}$ has reduced both the ketonic and nitro group. Correct answer given ...
0
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1answer
655 views

How is using Jones reagent different than Potassium dichromate in Sulfuric acid for the oxidation of alcohols?

I was taught at an institution I study in that using $\ce{K2Cr2O7}$ in the presence of $\operatorname{dil}.\ce{H2SO4}$ will oxidise $1^{\circ}$ alcohols to aldehydes, and $2^{\circ}$ alcohols to ...
3
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1answer
656 views

Which is the better leaving group in the following Cannizzaro reaction?

In the given mechanism, is it correct to prefer hydrogen as a better leaving group than the formyl group? The negative charge on an sp2 hybridized carbon, with the carbonyl group attached to it, ...
9
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1answer
7k views

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, ...
3
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1answer
524 views

I am confused about the stability of carbanion III and IV in the image

I am confused about the stability of carbanion III and IV in the image, I think III is more unstable because of electron donating effect (+R) of -OCH3 group but my book says III is more stable than ...
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811 views

Which enolate of butanone is more stable?

Consider butanone (A) and its two possible enolates B & C. Which of the two enolates will be more stable? B because of the more stable primary carbanion, or C because of more stable enolate (...
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174 views

pKa of different sites of butanone

From what I can tell, deprotonation of the central hydrogen leads to the more thermodynamically stable product (most substituted double bond. i.e. most stabilization by hyperconjugation). Therefore, ...
12
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2answers
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Regioselective enolate formation

Our professor only told us that A is favored, and B is not getting formed. I thought about the resonance structures and saw a contradiction to that what the prof told us. To be honest I think my ...
5
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1answer
689 views

Why does N-phenylhydroxylamine give Fehling's test?

I have studied that Fehling's test is given by aldehydes and alpha hydroxy ketones. I read in a book that it is also given by phenylhydroxylamine converting it to nitrosobenzene. Does it gives the ...
6
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1answer
3k views

Why is in the reaction of cyclic unsaturated aldehydes with hydrazine and hydrogen peroxide the aldehyde preserved?

Question What is the product of this reaction? The answer given: At first, I thought this was a typical Wolff-Kishner reduction, but then I saw the reagents didn't match up (no $\ce{OH-}$...
5
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1answer
99 views

What is the problem with forming 2,3-dimethylcyclohex-2-en-1-one?

I have suggested a mechanism for the formation of 3-ethyl-2-methylcyclohex-2-en-1-one A but the question says problems would be encountered if a similar route was used to make 2,3-dimethylcyclohex-2-...
5
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3answers
929 views

Which tautomer of hexane-2,4-dione is more stable?

Which tautomer will be more stable? Both 1 and 2 show intramolecular hydrogen bonding and form 6 membered cyclic ring, thus increasing the stability. I think I need to compare the effect of the two ...
5
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1answer
440 views

How to dialkylate a cyclohexene, and convert a carbonyl to an alkene?

I'm trying to design a synthesis of D from C. All I can think of is using $\ce{Me2CuLi}$ to add the methyl group to the alkene. I thought maybe then if isobutyl bromide was in the reaction mixture ...
3
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1answer
5k views

Can all species that undergo aldol reactions also undergo Cannizzaro reactions?

Can all species that undergo aldol reactions also undergo Cannizzaro reactions? Ater all, the nucleophile can always attack the carbonyl group.
2
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1answer
108 views

One-pot synthesis of pyrazole [closed]

I am trying to follow a published paper. It is a one-pot synthesis of pyrazole from a ketone and and acid chloride via a diketone intermediate. Here is the produre from the paper: General Procedure:...
2
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3answers
356 views

Conversion from t-butanol to alkene

How can I accomplish the above conversion? My thoughts: One way of introducing the double bond, would be using the appropriate Grignard Reagent after oxidation of t-butanol (somehow) I think that ...
7
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2answers
12k views

Which will be the most acidic hydrogen in the following organic compounds?

Which will be the most acidic hydrogen in both cases? Please explain. According to me, in the first compound 2 should be most acidic as in both 1 and 2, resonance occurs but 2’s carbon is closer to ...
7
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2answers
2k views

Why does no Robinson Annulation occur after the Michael addition?

Under basic conditions a Michael addition reaction can be used to convert compound A into product C. Explain why no Robinson annulation cyclic product is observed? Compound A Product C ...
8
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2answers
299 views

Is 2-oxobicyclo[2.2.1]heptan-1-ide resonance stabilized?

Is the following compound resonance stabilized? I think its not resonance stabilized because the p-orbital of carbanion and pure p-orbital of carbonyl carbon are not in same plane. So they can't ...
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2answers
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Prediction of products in reaction of dicarbonyl with alpha-haloketone

Following is the question that was asked in my exam. a,b,c,d are the various options, one of which is the answer. I am familiar with the Reformatsky reaction, Aldol condensation, Knoevenagel's ...
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1answer
1k views

Reaction of a vicinal diol with acetone

I have the first part correct; however, I can't seem to understand what the 2nd part's answer is. I realize the water leaves, but then what?
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1answer
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Why is acetyl cyanide not obtained from acetyl chloride?

Why doesn't acetyl chloride or any other aliphatic acyl chloride react with cyanide ions and undergo nucleophilic addition elimination to form aliphatic acyl cyanide, even though this reaction occurs ...
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2answers
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What are the products of the haloform reaction of acetylacetone?

I searched a lot to find the products of the haloform reaction of acetylacetone (pentane-2,4-dione), but I didn't find any results. What are the products of the haloform reaction of acetylacetone?
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1answer
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Does an acetal give a positive Tollens test?

In Organic Chemistry (Wade) there is a question: Which of the following compounds would give a positive Tollens' test? (Remember that the Tollens' test involves mild basic aqueous conditions.) The ...
6
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1answer
12k views

IUPAC name for citric acid

I wonder what the name is of the following structure is: I think it's something like 3-hyrodxypentanoic diacid However, I wasn't able to find how to name a side chain if it contains a $\ce{COOH}$ ...
5
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1answer
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How is phosphoryl chloride attaching an aldehyde to benzene?

This reaction was part of an organic scheme I was doing: I thought that $\ce{POCl3}$ just converts the OH group into Cl, but looking at the chemical formula for A, I noticed that A has an extra ...
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1answer
496 views

Rate of formation of hydrate in a carbonyl compound [closed]

When water in presence of any acid is added to a carbonyl compound, it leads to the formation of its hydrate. But how do we determine the rate of reaction? Is it done by checking the amount of partial ...
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0answers
80 views

How to determine the pH range at which maximum hydrate is present?

Question: Find the $\mathrm{pH}$ range at which maximum hydrate is present in a solution of oxaloacetic acid (given $\mathrm{pK_a}$ of $\ce{-COOH}$ in the left is $=2.2$ and on the right is $=3.98$)...
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2answers
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Is tropone aromatic?

Looking at resonance structure 1a, it doesn't seem that tropone is aromatic. However, the resonance structure 1b with $\ce{C+-O-}$ satisfies Hückel's rule for aromaticity. Is it correct to say that ...
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2answers
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Does acetamide respond positively to iodoform test?

This answer explains why acetic acid does not give a positive iodoform test. Does acetamide respond positively to the test?
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1answer
653 views

Base used in Claisen Condensation

Here's what I read about which base to use in Claisen Condensation reaction (two esters or ester + carbonyl compound forming a beta keto-ester or beta-diketone): The base used must not interfere ...
4
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1answer
8k views

Hydrolysis of cyclic acetal

What happens to 1,5-dimethyl-6,8-dioxabicyclo[3.2.1]octane when it is hydrolyzed under acidic conditions? I know that under acidic conditions the first thing to likely happen is protonation. Does it ...
5
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3answers
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Do the π-electrons from the C=O bond in tropone contribute to Hückel 's rule?

This is a continuation of Is tropone aromatic? I'm looking at the resonance form that does have the carbonyl double-bond, 1a. Can this resonance structure also be considered aromatic? Would the ...
7
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2answers
552 views

What is the driving force for imine formation?

I know this that when a primary amine is reacted with a carbonyl compound, an imine is formed: I'm wondering why the position of this equilibrium lies to the product side / right-hand side. Why is ...
4
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1answer
968 views

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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1answer
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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?
5
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1answer
492 views

Why are 3 equivalents of organolithium needed in synthesis of ketone from carboxylic acid?

For the reaction of a carboxylic acid and organolithium reagents to synthesise a ketone, Clayden's, on p 219, mentions: Notice that three equivalents of organolithium are needed in this reaction: ...
14
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1answer
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Mechanism for basic hydrolysis of α-chloronitrile to ketone?

In Corey's 1969 prostaglandin synthesis,1 compound 2 is formed from compound 1 by: [...] treatment with 2.5 equiv of potassium hydroxide (added as a hot saturated aqueous solution) in dimethyl ...
11
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1answer
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Is an ester or a ketone more acidic?

Two organic chemistry textbooks I've read (by Bruice and by Tandon) say: Esters are more acidic than ketones, because the resonance between the two oxygen atoms gives less opportunity for the ...
0
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1answer
417 views

Reaction of vicinal diol in presence of benzaldehyde

Could someone please help me figure out the products of the following reaction? Here are few possibilities I've come up with: The attacking reagent could the given vicinal diol, with its ...
5
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2answers
971 views

What is the mechanism for thermal decarboxylation of a generic carboxylic acid (not special cases like beta-ketocarboxylic acid or malonic acids)?

I am looking for the mechanism for thermal decarboxylation for any RCOOH, and I am guessing that its possible for the thermal energy to cleave the R-C bond homolytically leaving a R• and •COOH. Then I ...
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0answers
832 views

Why does benzaldehyde undergo Cannizzaro reaction?

Benzaldehyde has an aromatic ring in it which has a pi cloud of electrons surrounding it. Would they not repel the nucleophile when it attacks?
6
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1answer
151 views

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 ...
12
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1answer
372 views

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 $\ce{H2}$ ...
4
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0answers
193 views

Stability of extended enolates

I'd expect an extended enolate to be more stable than a normal enolate, when both can form, but my textbook suggests otherwise. What is the stability of an extended enolate compared with a normal ...
5
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1answer
4k views

Product of primary amine and acid anhydride

How does an acid anhydride react with a primary amine? I thought it'll be some sort of condensation reaction, so I made the product by removing a water molecule and got a cyclic product. However, the ...
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1answer
112 views

Why can hydroxide not be used to synthesise ethanol from ethyl amine?

In the following reaction we have to find A and B. I thought that A could be $\ce{Br_2}$/$\ce{KOH}$ resulting in a Hoffmann bromide reaction. For B, I thought I would need a base such as $\ce{KOH,...