Why is dilute base used in aldol condensation?
Well, we know that we use dilute base in Aldol Condensation because In Aldol Condensation we have a Aldehyde or ketone having alpha Hydrogen ( which should be acidic in nature) , now as we know that OH- is a Nucleophilic base i.e it can act both as a base and as a Nucleophile (when acidic Hydrogen is absent).
Which base should be used for an aldol condensation?
As long as the reaction is kept cold, a beta-hydroxyaldehyde (often called an “aldol”) or a beta-hydroxyketone product can be isolated. Since the only electrophile present is the aldehyde/ketone, a weaker base such as NaOH or NaOCH3 can be used.
What is the role of sodium hydroxide in aldol condensation?
NaOH it undergoes self condensation as it contains alpha-hydrogen atom in its compound forming β-hydroxyaldehyde (an aldol) namely 3-Hydroxy butanal. This compound upon further heating will eliminate a molecule of water forming aldol condensation product namely Crotonaldehyde Or But-2-en-al.
What happens when acetone undergoes aldol condensation?
When treated with Ba(OH)2, acetone undergoes aldol condensation to form diacetone alcohol.
Is base catalyst in aldol condensation?
In an aldol condensation, an enolate ion reacts with a carbonyl compound in the presence of acid/base catalyst to form a β-hydroxy aldehyde or β-hydroxy ketone, followed by dehydration to give a conjugated enone. It is a useful carbon-carbon bond-forming reaction.
Does aldol condensation require heat?
Intramolecular aldol reaction As with other aldol reaction the addition of heat causes an aldol condensation to occur.
Which of the following will not give aldol condensation?
Benzaldehyde will not give aldol condensation due to absence of α-H atom.
Which undergoes aldol condensation in the presence of dilute NaOH?
Acetaldehyde
Assertion : Acetaldehyde undergoes aldol condensation with dil. NaOH.
Where does aldol condensation occur?
Aldol condensation occurs in aldehydes having α-hydrogen with a dilute base to give β-hydroxy aldehydes called aldols.
Why benzldehyde does not show aldol condensation reaction with dilute NaOH?
To occur the aldol condensation, there should be both alpha hydrogen and alpha carbon atom in the aldehydde or ketone. In the benzaldehyde, there is an alpha carbon atom. But there is no alpha hydrogen atoms. So benzldehyde does not have chance to react with dilute NaOH to show aldol condensation reaction.
Which of the following can be used as reagents for aldol condensation?
Dilue NaOH, KOH, Ba (OH) 2 can be used as reagents for aldol condensation. Reaction is stared by OH – ions provided from strong alkali. At the end of reaction, OH – ions are regenerated again. Therefore OH – ions are behaved as a catalyst. Also OH – ions are behaved as nucleophiles.
What is a crossed aldol reaction?
The condensation reaction between two different molecules of an aldehyde or ketone in a protic solvent such as water or alcohol constitutes the crossed aldol reaction. When condensation is between two different carbonyl compounds, it is called crossed aldol condensation.