Which aldehyde can undergo aldol condensation?
All the aldehydes having α-hydrogen undergo Aldol condensation.
Which of the following Cannot give condensation reaction with acetaldehyde?
The carbonyl compounds must contain an α− hydrogen atom to undergo aldol condensation. Thus, propanal and ethanal are the aldehydes that can undergo aldol condensation. Thus, aldehydes that do not undergo aldol condensation are trichloroethanal, benzaldehyde and methanal.
Which molecule possibly shows aldol condensation reaction?
In its usual form, it involves the nucleophilic addition of a ketone enolate to an aldehyde to form a β-hydroxy ketone, or “aldol” (aldehyde + alcohol), a structural unit found in many naturally occurring molecules and pharmaceuticals….
| Aldol condensation | |
|---|---|
| RSC ontology ID | RXNO:0000017 |
Why does acetaldehyde undergo aldol condensation?
Aldehydes having at least one α−H undergo Aldol condensation in the presence of a base to give α− hydroxy aldehydes (aldol). Since acetaldehyde has carbon so it goes under aldol condensation.
Why do aldehydes undergo aldol condensation?
Aldol reaction happens in aldehydes and ketones if the compounds contain no less than one α-hydrogen. The β-hydroxy aldehydes or aldol and β-hydroxy ketones or ketol lose water molecules easily to produce α, β-unsaturated carbonyl compounds. These compounds are aldol condensation products.
Why acetaldehyde does not undergo aldol condensation?
Aldehydes having at least one α−H undergo Aldol condensation in the presence of a base to give α− hydroxy aldehydes (aldol). Since acetaldehyde CH3CHO has α−H whereas formaldehyde HCHO has no α−H , therefore the former can undergo aldol condensation while later does not.
Which of following will not give aldol condensation?
Benzaldehyde will not give aldol condensation due to absence of α-H atom.
What will be the major product when acetaldehyde condenses with excess with benzaldehyde?
As the acetaldehyde adds to the reaction mixture, the base will remove a proton to form the enolate anion, which will be surrounded by benzaldehyde, but not much acetaldehyde. The major reaction will be acetaldehyde enolate reacting with benzaldehyde.
Is benzaldehyde a ketone or aldehyde?
Except where otherwise noted, data are given for materials in their standard state (at 25 °C [77 °F], 100 kPa). Benzaldehyde (C6H5CHO) is an organic compound consisting of a benzene ring with a formyl substituent. It is the simplest aromatic aldehyde and one of the most industrially useful.
Does acetaldehyde have alpha hydrogen?
The structure of Trichloro acetaldehyde is, There is an alpha carbon but no alpha hydrogen is present in the compound.
What is aldol condensation reaction explain using acetaldehyde as example?
Hint: Aldol condensation is the reaction when two aldehydes that are same or different react together in the presence of dilute alkali to form a product intermediate that has an aldehyde and alcohol, called as aldol. This aldol on dehydration gives alpha, beta – unsaturated carbonyl compounds.
What is the cross aldol condensation of acetaldehyde with benzaldehyde?
The crossed aldol condensation of acetaldehyde with benzaldehyde is aided by the fact that benzaldehyde bears no alpha-protons. However, a possible competitive reaction is the “self-condensation” of two molecules of acetaldehyde.
What are aldol condensation reactions and how do they work?
Aldol condensation reactions are one of the most important reactions of organic chemistry as they provide a good way to form carbon-carbon bonds. In these reactions, an enol or an enolate ion reacts with a carbonyl compound to form a β-hydroxy aldehyde or a β-hydroxy ketone and undergoes dehydration to give a conjugated enone.
What is the reaction mechanism for condensation of benzaldehyde with acetone?
General reaction mechanism for the condensation of one molecule of benzaldehyde with one molecule of acetone. With heating, this product eliminates water (dehydration) to form an α,β- unsaturated ketone. This happens first by a deprotonation step (step 4) with sodium hydroxide to form a resonance-stabilized carbanion.
Can aldehydes without alpha carbon and alpha hydrogen do aldol condensation?
Aldehydes without alpha carbon and alpha hydrogen does not have the ability to do aldol condensation. As examples, formaldehyde and benzaldehyde can be given. Formaldehyde does not have alpha carbon and benzaldehyde does not have alpha hydrogen.