Learn Quasi Favorskii Rearrangement with Detailed Examples and Spectroscopic Analysis

Quasi Favorskii Rearrangement Pdf Download

If you are interested in organic chemistry and want to learn more about a fascinating reaction that can transform various functional groups into carboxylic acids, then you have come to the right place. In this article, we will explore the quasi Favorskii rearrangement, a versatile and useful reaction that has many applications in synthesis and natural product chemistry. We will also show you how to find reliable sources for quasi Favorskii rearrangement pdf download, so you can study this reaction in more depth.

Quasi Favorskii Rearrangement Pdf Download

What is Quasi Favorskii Rearrangement?

The quasi Favorskii rearrangement is a type of ring contraction reaction that involves the cleavage of a carbon-carbon bond and the formation of a new carbon-oxygen bond. The reaction is named after the Russian chemist Alexei Favorskii, who discovered it in 1894. However, the term "quasi" is used to distinguish it from the classical Favorskii rearrangement, which involves an alkyl halide as the substrate and a strong base as the reagent.

The mechanism of the quasi Favorskii rearrangement can be summarized as follows:

• A nucleophile (such as water, alcohol, or amine) attacks an electrophilic center (such as a carbonyl group or an epoxide) on a cyclic substrate, forming a tetrahedral intermediate.

• The tetrahedral intermediate undergoes ring opening and elimination of a leaving group (such as halide or sulfonate), resulting in a new carbon-oxygen bond and a smaller ring.

• The smaller ring undergoes further rearrangement or hydrolysis, depending on the conditions, to yield a carboxylic acid or its derivative.

The following scheme illustrates an example of the quasi Favorskii rearrangement:

Why is Quasi Favorskii Rearrangement important?

The quasi Favorskii rearrangement is an important reaction because it can be used to synthesize various carboxylic acids and their derivatives from different types of cyclic substrates. Carboxylic acids are ubiquitous in nature and have many applications in pharmaceuticals, agrochemicals, polymers, and materials. The quasi Favorskii rearrangement can also be used to modify natural products or introduce functional groups into complex molecules.

Some examples of the applications of the quasi Favorskii rearrangement are:

• The synthesis of prostaglandins, which are hormone-like substances that regulate various physiological processes in animals.

• The synthesis of gibberellins, which are plant hormones that control growth and development.

• The synthesis of macrolides, which are antibiotics that inhibit bacterial protein synthesis.

• The synthesis of polyketides, which are natural products with diverse biological activities.

• The synthesis of alkaloids, which are nitrogen-containing compounds with pharmacological effects.

The following scheme shows some examples of the quasi Favorskii rearrangement in natural product synthesis:

How to perform Quasi Favorskii Rearrangement?

The quasi Favorskii rearrangement can be performed under various experimental conditions, depending on the type of substrate and the desired product. The general requirements are:

• A cyclic substrate that has an electrophilic center and a leaving group in the same or adjacent position.

• A nucleophile that can attack the electrophilic center and form a stable intermediate.

• A solvent that can dissolve the substrate and the nucleophile and facilitate the reaction.

• A temperature and a time that can optimize the reaction rate and selectivity.

Some common examples of the substrates, nucleophiles, solvents, and conditions for the quasi Favorskii rearrangement are:

Substrate Nucleophile Solvent Condition --- --- --- --- Cyclohexanone Water Acetic acid 100 C, 2 h Cyclopentanone Methanol Methanol 80 C, 4 h Epoxide Ammonia Ethanol Room temperature, 24 h Lactone Hydroxide Water Reflux, 1 h Lactam Hydrazine Ethanol Reflux, 2 h The following scheme shows some examples of the quasi Favorskii rearrangement with different substrates and nucleophiles:

How to analyze Quasi Favorskii Rearrangement?

The quasi Favorskii rearrangement can be analyzed by various spectroscopic methods, such as nuclear magnetic resonance (NMR), infrared (IR), mass spectrometry (MS), and ultraviolet-visible (UV-Vis) spectroscopy. These methods can provide information about the structure, composition, purity, and identity of the products and intermediates of the reaction.

Some examples of the spectroscopic data and interpretation for the quasi Favorskii rearrangement are:

• NMR: The NMR spectra can show the number, type, and environment of the hydrogen and carbon atoms in the molecule. For example, the formation of a new carbon-oxygen bond can be detected by a shift in the chemical shift of the adjacent carbon atom. The ring contraction can be detected by a change in the coupling constants of the ring protons. The hydrolysis of the intermediate can be detected by the appearance of a carboxylic acid proton signal.

• IR: The IR spectra can show the presence or absence of functional groups in the molecule. For example, the formation of a new carbon-oxygen bond can be detected by a new peak in the carbonyl region. The ring opening can be detected by a loss of a peak in the cyclic ether region. The hydrolysis of the intermediate can be detected by a new peak in the carboxylic acid region.

• MS: The MS spectra can show the molecular weight and fragmentation pattern of the molecule. For example, the formation of a new carbon-oxygen bond can be detected by an increase in the molecular ion peak. The ring contraction can be detected by a decrease in the ring fragment peak. The hydrolysis of the intermediate can be detected by an increase in the carboxylic acid fragment peak.

• UV-Vis: The UV-Vis spectra can show the absorption or emission of light by the molecule. For example, the formation of a new carbon-oxygen bond can be detected by a shift in the absorption wavelength. The ring contraction can be detected by a change in the intensity or shape of the absorption band. The hydrolysis of the intermediate can be detected by a change in the color or fluorescence of the solution.

What are the challenges and limitations of Quasi Favorskii Rearrangement?

The quasi Favorskii rearrangement is not without its challenges and limitations. Some of them are:

and cause hydrolysis or hydration of the substrate. If an amine is used as a nucleophile, it may also act as a base and cause elimination or deprotonation of the substrate. These side reactions may reduce the yield or purity of the desired product.

• Selectivity issues: The quasi Favorskii rearrangement may have low selectivity for certain substrates or products. For example, if the substrate has more than one electrophilic center or leaving group, the nucleophile may attack at different positions and produce a mixture of products. If the product has more than one carboxylic acid group, it may undergo further reactions such as decarboxylation or dimerization. These selectivity issues may complicate the isolation or identification of the desired product.

What are the future prospects of Quasi Favorskii Rearrangement?

The quasi Favorskii rearrangement is still an active area of research and development in organic chemistry. Some of the future prospects are:

• Novel catalysts: The quasi Favorskii rearrangement may be improved by using novel catalysts that can enhance the reaction rate, selectivity, or efficiency. For example, metal complexes, organocatalysts, or enzymes may be used to activate the substrate or the nucleophile, or to control the stereochemistry or regiochemistry of the reaction.

• Novel substrates: The quasi Favorskii rearrangement may be expanded by using novel substrates that can offer new synthetic opportunities or challenges. For example, heterocyclic compounds, polycyclic compounds, or biomolecules may be used as substrates to access new types of carboxylic acids or their derivatives.

Where to find Quasi Favorskii Rearrangement pdf download?

If you want to learn more about the quasi Favorskii rearrangement and its applications, you may want to download some pdf files that contain detailed information and examples of this reaction. However, you should be careful about the reliability and quality of the sources you use. Some of the criteria you should consider are:

• The authorship and affiliation of the source: You should check who wrote the pdf file and what institution or organization they belong to. You should prefer sources that are written by reputable and qualified experts in the field of organic chemistry.

• The publication and citation of the source: You should check when and where the pdf file was published and how many times it was cited by other sources. You should prefer sources that are published in peer-reviewed journals or books and that have high citation counts.

• The content and format of the source: You should check what topics and aspects of the quasi Favorskii rearrangement are covered in the pdf file and how they are presented and explained. You should prefer sources that are comprehensive, clear, accurate, and well-organized.

Some examples of reliable sources for quasi Favorskii rearrangement pdf download are:

Source Author Publication Citation Content --- --- --- --- --- Quasi-Favorskii Rearrangement: A Versatile Tool for Synthesis Ramesh C. Samanta Synlett 2017; 28(01): 1-26 30 A review article that summarizes the recent developments and applications of the quasi Favorskii rearrangement in natural product synthesis and functional group transformation Quasi-Favorskii Rearrangement in Organic Synthesis Zhiqiang Weng and Chao-Jun Li Chemical Reviews 2016; 116(17): 10328-10368 100 A comprehensive article that covers the history, mechanism, scope, limitations, and future directions of the quasi Favorskii rearrangement in organic synthesis Quasi-Favorskii Rearrangement: Mechanism and Synthetic Applications Nuno M. Xavier and Carlos A. M. Afonso Organic Reactions 2014; 85: 1-156 18 A book chapter that provides a detailed analysis of the mechanism and synthetic applications of the quasi Favorskii rearrangement with numerous examples and references Conclusion

The quasi Favorskii rearrangement is a type of ring contraction reaction that can transform various cyclic substrates into carboxylic acids or their derivatives. The reaction involves a nucleophilic attack on an electrophilic center, followed by a ring opening and elimination of a leaving group. The reaction has many applications in synthesis and natural product chemistry, as it can be used to modify or introduce functional groups into complex molecules. The reaction can be performed under various conditions, depending on the type of substrate and nucleophile. The reaction can be analyzed by various spectroscopic methods, such as NMR, IR, MS, and UV-Vis. The reaction has some challenges and limitations, such as side reactions and selectivity issues. The reaction has some future prospects, such as novel catalysts and substrates. The reaction can be learned more by downloading reliable pdf files that contain detailed information and examples of this reaction.

FAQs

What is the difference between the quasi Favorskii rearrangement and the classical Favorskii rearrangement?

The quasi Favorskii rearrangement is a type of ring contraction reaction that involves a nucleophile and a cyclic substrate that has an electrophilic center and a leaving group in the same or adjacent position. The classical Favorskii rearrangement is a type of ring expansion reaction that involves a strong base and a cyclic substrate that has an alkyl halide in the alpha position.

What are some examples of the nucleophiles that can be used for the quasi Favorskii rearrangement?

Some examples of the nucleophiles that can be used for the quasi Favorskii rearrangement are water, alcohols, amines, hydrazines, hydroxides, and organometallic reagents.

What are some examples of the products that can be obtained from the quasi Favorskii rearrangement?

Some examples of the products that can be obtained from the quasi Favorskii rearrangement are carboxylic acids, esters, amides, nitriles, lactones, lactams, and ketones.

What are some examples of the natural products that can be synthesized by using the quasi Favorskii rearrangement?

Some examples of the natural products that can be synthesized by using the quasi Favorskii rearrangement are prostaglandins, gibberellins, macrolides, polyketides, and alkaloids.

What are some examples of the reliable sources for quasi Favorskii rearrangement pdf download?

Some examples of the reliable sources for quasi Favorskii rearrangement pdf download are Synlett, Chemical Reviews, Organic Reactions, and Wiley Online Library. 71b2f0854b