Logo
Log in
Logo
Log inSign up
Logo

Tools

AI Concept MapsAI Mind MapsAI Study NotesAI FlashcardsAI Quizzes

Resources

BlogTemplate

Info

PricingFAQTeam

info@algoreducation.com

Corso Castelfidardo 30A, Torino (TO), Italy

Algor Lab S.r.l. - Startup Innovativa - P.IVA IT12537010014

Privacy PolicyCookie PolicyTerms and Conditions

Claisen Condensation

Claisen Condensation is an essential reaction in organic chemistry, named after Ludwig Claisen. It forms carbon-carbon bonds by condensing esters or carbonyl compounds using a strong base, leading to β-keto esters or β-diketones. This reaction is fundamental in the biosynthesis of fatty acids and polyketides, and its variations, such as the Claisen-Schmidt and Crossed Claisen Condensations, are crucial for synthesizing complex organic molecules and pharmaceuticals.

See more
Open map in editor

1

4

Open map in editor

Want to create maps from your material?

Insert your material in few seconds you will have your Algor Card with maps, summaries, flashcards and quizzes.

Try Algor

Learn with Algor Education flashcards

Click on each Card to learn more about the topic

1

Claisen Condensation: Reactants involved

Click to check the answer

Involves esters or ester and another carbonyl compound.

2

Claisen Condensation: Role of base

Click to check the answer

Strong base required to deprotonate ester, initiating condensation.

3

Claisen Condensation: Products formed

Click to check the answer

Results in β-keto ester or β-diketone.

4

During Claisen Condensation, the enolate ion attacks the ______ carbon of another ester, leading to the formation of a β-keto ester such as ______ acetoacetate.

Click to check the answer

carbonyl ethyl

5

Ideal base for Claisen Condensation

Click to check the answer

Must be strong enough to deprotonate α-hydrogen, forming enolate ion.

6

Preferred solvent type for Claisen Condensation

Click to check the answer

Polar aprotic solvents are often used to facilitate the reaction.

7

Upon dehydration, the product of the Claisen-Schmidt Reaction becomes an ,β- ester, useful in creating complex organic structures.

Click to check the answer

α unsaturated

8

Influence of ester nature on Claisen Condensation selectivity

Click to check the answer

Ester's steric and electronic properties affect Claisen Condensation's pathway and product selectivity.

9

Potential side reactions at elevated temperatures in Claisen Condensation

Click to check the answer

High temps may cause decarboxylation or transesterification, leading to undesired byproducts.

10

In ______ ______ Condensation, two distinct esters or an ester and another carbonyl compound react together.

Click to check the answer

Crossed Claisen

11

Using ______ ______ and ethyl formate with sodium ethoxide leads to the production of ethyl 2-benzyloxy-3-oxobutanoate.

Click to check the answer

ethyl benzoate

12

Claisen Condensation role in drug synthesis

Click to check the answer

Essential for creating barbiturates, a class of sedative and sleep-inducing drugs.

13

Claisen Condensation in materials science

Click to check the answer

Used to synthesize conjugated polymers for electronic devices, like OLEDs.

14

Educational importance of Claisen Condensation

Click to check the answer

Teaches ester condensation reactions, a key concept in organic chemistry courses.

15

The ______ ion produced in the Claisen Condensation reacts with another ester, resulting in a ______ or a β-diketone.

Click to check the answer

enolate β-keto ester

16

Variations of Claisen Condensation

Click to check the answer

Include Claisen-Schmidt and Crossed Claisen, expanding utility in synthesis.

17

Significance of Claisen Condensation in practical applications

Click to check the answer

Used in drug synthesis, material science, and education for C-C bond formation.

Q&A

Here's a list of frequently asked questions on this topic

Similar Contents

Chemistry

Cycloaddition Reactions in Organic Chemistry

View document

Chemistry

Heteroatoms in Organic Chemistry

View document

Chemistry

Alkene Nomenclature

View document

Chemistry

Organic Chemistry and Its Applications

View document

Introduction to Claisen Condensation in Organic Synthesis

Claisen Condensation is a pivotal reaction in organic synthesis, named after the German chemist Ludwig Claisen. This reaction is crucial for the formation of carbon-carbon bonds and typically involves the condensation of esters or an ester with another carbonyl compound in the presence of a strong base, resulting in the formation of a β-keto ester or a β-diketone. Claisen Condensation is not only important in laboratory synthesis but also plays a vital role in biological pathways, such as the biosynthesis of fatty acids and polyketides.
Glass flask with bright yellow liquid for distillation in chemical laboratory, reflections on shiny surface with blurred background of laboratory equipment.

The Mechanism of Claisen Condensation

The Claisen Condensation mechanism involves several steps. Initially, a strong base deprotonates the α-hydrogen of an ester to generate an enolate ion. This enolate ion then acts as a nucleophile and attacks the electrophilic carbonyl carbon of another ester molecule. Subsequent elimination of the alkoxy group from the tetrahedral intermediate results in the formation of a new carbon-carbon bond, yielding a β-keto ester. For instance, the condensation of two molecules of ethyl acetate in the presence of sodium ethoxide yields ethyl acetoacetate.

Essential Components and Factors Affecting Claisen Condensation

Claisen Condensation requires three essential components: an ester or carbonyl compound with an α-hydrogen, a strong base, and a suitable solvent. The choice of base is critical, as it must be strong enough to deprotonate the α-hydrogen to form the enolate ion. Solvent choice, reaction temperature, and reactant concentration also influence the reaction. For example, polar aprotic solvents are often used to facilitate the reaction, and precise temperature control can prevent side reactions.

Claisen-Schmidt Reaction: An Aldol Condensation Variant

The Claisen-Schmidt Reaction, also known as the Aldol Condensation, is a variant of the Claisen Condensation that involves an ester and an aldehyde or ketone. This reaction typically proceeds at room temperature and produces a β-hydroxy ester, which can undergo dehydration to yield an α,β-unsaturated ester. The Claisen-Schmidt Reaction is particularly valuable for constructing complex organic molecules and is utilized in the synthesis of biologically active compounds, including flavonoids and other natural products.

Applications of Claisen Condensation in Organic Synthesis

Claisen Condensation is a versatile tool in organic synthesis, enabling the construction of complex molecules such as polyketides and fatty acids. The reaction is particularly useful for creating β-keto esters and β-diketones, which are important intermediates in various synthetic pathways. However, the reaction's selectivity can be influenced by the nature of the ester used, and elevated temperatures may lead to side reactions such as decarboxylation or transesterification.

Crossed Claisen Condensation: Selectivity Challenges

Crossed Claisen Condensation involves the reaction between two different esters or an ester and a different carbonyl compound. This reaction can be complex due to the possibility of multiple products. However, with judicious choice of reactants and reaction conditions, it is possible to achieve selective carbon-carbon bond formation. An illustrative example is the reaction between ethyl benzoate and ethyl formate in the presence of sodium ethoxide, which yields ethyl 2-benzyloxy-3-oxobutanoate.

The Widespread Impact of Claisen Condensation

Claisen Condensation has a significant impact across various scientific disciplines, including pharmaceutical development, materials science, and the potential production of biofuels. It is essential for the synthesis of certain drugs, such as barbiturates, and for the creation of conjugated polymers used in electronic devices. Additionally, the reaction is a fundamental topic in the organic chemistry curriculum, equipping students with knowledge of ester condensation reactions and their practical applications.

Substrate and Product Dynamics in Claisen Condensation

In Claisen Condensation, the substrates are typically esters with an acidic α-hydrogen, which is abstracted by a strong base to form an enolate ion. The enolate ion then attacks another ester molecule, leading to the formation of a β-keto ester or β-diketone. The reaction's efficiency depends on the proper interaction between the substrates and the base, emphasizing the importance of understanding the roles of these components in the reaction mechanism.

Conclusion: The Significance of Claisen Condensation

Claisen Condensation is a cornerstone of organic chemistry, enabling the synthesis of complex molecules and playing a vital role in both synthetic and biological chemistry. Its variations, such as the Claisen-Schmidt and Crossed Claisen Condensations, expand its utility and application. The reaction's ability to form carbon-carbon bonds is invaluable, and its significance is reflected in its widespread use in drug synthesis, material science, and educational settings.