The benzoin addition is an addition reaction involving two aldehydes. The reaction generally occurs between aromatic aldehydes or glyoxals. The reaction produces an acyloin. In the classic application benzaldehyde is converted to benzoin
The document summarizes ozonolysis, which is the reaction of ozone with alkenes, alkynes, and azo compounds. Ozonolysis of alkenes forms an ozonide intermediate that can be converted to alcohols, aldehydes, ketones, or carboxylic acids depending on the workup. Alkynes undergo ozonolysis to form diketones or carboxylic acids. Ozonolysis has applications in synthesizing aldehydes, ketones, and drugs, and can be used to determine double bond locations in unknown alkenes.
Addition reactions occur when two reactants combine to form a new product with no leftover atoms. In an addition reaction, new groups are added to the starting material, breaking a pi bond and forming two sigma bonds. Addition reactions involve the addition of electrophiles, radicals, or nucleophiles across multiple bonds such as carbon-carbon double or triple bonds.
This document discusses the molecular orbital diagram of benzene and electrophilic substitution reactions. It describes how benzene has delocalized pi molecular orbitals formed from the unhybridized p orbitals of each carbon atom. Nitration and halogenation are given as examples of electrophilic substitution reactions, where an electrophile such as the nitronium ion or chloronium ion attacks the benzene ring. The mechanisms of these reactions involve the formation of an electrophile, then a sigma complex intermediate, followed by formation of the final substituted product. Friedel-Crafts reactions like alkylation and acylation are also discussed as types of electrophilic substitutions catalyzed by Lewis acids.
Ozonolysis is a reaction that cleaves carbon-carbon double bonds in alkenes using ozone, producing more oxidized carbonyl compounds such as aldehydes and ketones. The reaction occurs in several steps: ozone adds to the alkene to form an unstable molozonide intermediate which then rearranges to an ozonide. The ozonide is then treated with a reducing agent like zinc or dimethyl sulfide to yield carbonyl products, or an oxidizing agent like hydrogen peroxide to yield carboxylic acids.
This document presents information about the Perkin reaction, which was discovered in the 19th century by English chemist William Henry Perkin. The Perkin reaction is an aldol condensation that converts an aromatic aldehyde and an acid anhydride to an alpha beta unsaturated cinnamic acid. It involves a four step mechanism - abstraction of alpha hydrogen from the acid anhydride, attack of the carbanion on the carbonyl carbon of benzaldehyde, an intramolecular acetyl shift, and loss of the acetate ion to form the unsaturated carboxylic acid product. The Perkin reaction is used to synthesize cinnamic acids, phytoestrogens, stilbenes, and resver
The document discusses aldol condensation, an organic reaction where two molecules of an aldehyde or ketone undergo a condensation reaction in the presence of a base to yield a β–hydroxyaldehyde or β–hydroxyketone. It involves the reaction of an enolate ion, formed from deprotonation of an aldehyde, with a carbonyl compound to form an aldol. This may then undergo dehydration to form a conjugated enone. The mechanism proceeds through enolate formation, carbon-carbon bond formation between the enolate and carbonyl, and protonation to form the aldol intermediate. Crossed aldol condensation refers to the reaction between two different aldehyde or ketone
This power point presentation summarizes elimination reactions, specifically 1,2 elimination reactions. It defines elimination reactions as reactions where two atoms or groups are removed from a reactant to form an unsaturated product. 1,2 elimination reactions eliminate atoms or groups from the 1 and 2 positions on a molecule. Three possible mechanisms are discussed: E2, E1, and E1cb. Evidence for the E2 mechanism includes kinetic isotope effects, the element effect showing dependence on leaving group ability, and the lack of hydrogen exchange. The Saytzeff rule and factors influencing its application, like stability and transition state crowding, are also covered.
IMPORTANT NAMED REACTIONS in Organic synthesis with Introduction, General Mechanism, and their synthetic application covering more than 20 named reactions in it.
The document summarizes ozonolysis, which is the reaction of ozone with alkenes, alkynes, and azo compounds. Ozonolysis of alkenes forms an ozonide intermediate that can be converted to alcohols, aldehydes, ketones, or carboxylic acids depending on the workup. Alkynes undergo ozonolysis to form diketones or carboxylic acids. Ozonolysis has applications in synthesizing aldehydes, ketones, and drugs, and can be used to determine double bond locations in unknown alkenes.
Addition reactions occur when two reactants combine to form a new product with no leftover atoms. In an addition reaction, new groups are added to the starting material, breaking a pi bond and forming two sigma bonds. Addition reactions involve the addition of electrophiles, radicals, or nucleophiles across multiple bonds such as carbon-carbon double or triple bonds.
This document discusses the molecular orbital diagram of benzene and electrophilic substitution reactions. It describes how benzene has delocalized pi molecular orbitals formed from the unhybridized p orbitals of each carbon atom. Nitration and halogenation are given as examples of electrophilic substitution reactions, where an electrophile such as the nitronium ion or chloronium ion attacks the benzene ring. The mechanisms of these reactions involve the formation of an electrophile, then a sigma complex intermediate, followed by formation of the final substituted product. Friedel-Crafts reactions like alkylation and acylation are also discussed as types of electrophilic substitutions catalyzed by Lewis acids.
Ozonolysis is a reaction that cleaves carbon-carbon double bonds in alkenes using ozone, producing more oxidized carbonyl compounds such as aldehydes and ketones. The reaction occurs in several steps: ozone adds to the alkene to form an unstable molozonide intermediate which then rearranges to an ozonide. The ozonide is then treated with a reducing agent like zinc or dimethyl sulfide to yield carbonyl products, or an oxidizing agent like hydrogen peroxide to yield carboxylic acids.
This document presents information about the Perkin reaction, which was discovered in the 19th century by English chemist William Henry Perkin. The Perkin reaction is an aldol condensation that converts an aromatic aldehyde and an acid anhydride to an alpha beta unsaturated cinnamic acid. It involves a four step mechanism - abstraction of alpha hydrogen from the acid anhydride, attack of the carbanion on the carbonyl carbon of benzaldehyde, an intramolecular acetyl shift, and loss of the acetate ion to form the unsaturated carboxylic acid product. The Perkin reaction is used to synthesize cinnamic acids, phytoestrogens, stilbenes, and resver
The document discusses aldol condensation, an organic reaction where two molecules of an aldehyde or ketone undergo a condensation reaction in the presence of a base to yield a β–hydroxyaldehyde or β–hydroxyketone. It involves the reaction of an enolate ion, formed from deprotonation of an aldehyde, with a carbonyl compound to form an aldol. This may then undergo dehydration to form a conjugated enone. The mechanism proceeds through enolate formation, carbon-carbon bond formation between the enolate and carbonyl, and protonation to form the aldol intermediate. Crossed aldol condensation refers to the reaction between two different aldehyde or ketone
This power point presentation summarizes elimination reactions, specifically 1,2 elimination reactions. It defines elimination reactions as reactions where two atoms or groups are removed from a reactant to form an unsaturated product. 1,2 elimination reactions eliminate atoms or groups from the 1 and 2 positions on a molecule. Three possible mechanisms are discussed: E2, E1, and E1cb. Evidence for the E2 mechanism includes kinetic isotope effects, the element effect showing dependence on leaving group ability, and the lack of hydrogen exchange. The Saytzeff rule and factors influencing its application, like stability and transition state crowding, are also covered.
IMPORTANT NAMED REACTIONS in Organic synthesis with Introduction, General Mechanism, and their synthetic application covering more than 20 named reactions in it.
The benzoin condensation is a reaction between two molecules of benzaldehyde catalyzed by cyanide ions to form benzoin. It was first reported in 1832 by Liebig and Wöhler. It involves a cyanide ion forming a cyanohydrin intermediate with benzaldehyde, followed by a condensation reaction between the cyanohydrin and another benzaldehyde molecule. This forms benzoin along with the removal of cyanide ions. Benzoin condensation is useful for organic synthesis and producing polymers.
The document discusses elimination reactions of alkyl halides. It begins by defining elimination reactions as those that involve the loss of elements from a starting material to form a new pi bond in the product. Specifically, it focuses on dehydrohalogenation reactions, where removal of HX occurs. The most common mechanism is E2 elimination, which is a bimolecular reaction promoted by a strong base. It follows second-order kinetics and has a single transition state. The document discusses characteristics of E2 reactions like Saytzeff's rule, Markovnikov's rule, anti-Markovnikov reactions, stereochemistry and stereoselectivity.
Electrophilic substitution reactions involve replacing a hydrogen atom in an aromatic ring with an electrophilic group such as nitro, halogen, sulfonic acid or alkyl/acyl groups. This is done using electrophiles generated in situ with a Lewis acid catalyst. It proceeds by generation of an electrophile, formation of a carbocation intermediate through attack on the aromatic ring, and removal of a proton. Ortho/para directing groups activate the ring towards substitution at those positions, while meta directing groups deactivate the ring at ortho/para positions. Polynuclear aromatic hydrocarbons with more than two fused benzene rings can be carcinogenic if inhaled from incomplete combustion.
The Perkin reaction is an organic reaction that produces α,β-unsaturated aromatic acids by condensing an aromatic aldehyde with an aliphatic acid anhydride in the presence of a weak base. The reaction was first discovered by William Henry Perkin in 1868. It involves the removal of water through condensation and produces the desired unsaturated carboxylic acid. Some examples of the Perkin reaction include converting furfural to furylacrylic acid, forming coumaric acid from salicylaldehyde which can then be dehydrated to coumarin, and synthesizing the phytoestrogenic compound resveratrol.
The aldol condensation reaction allows carbonyl compounds containing an α-hydrogen atom to undergo condensation. It is a reversible reaction that proceeds through an enolate intermediate formed when hydroxide deprotonates the α-hydrogen. The enolate then acts as a nucleophile that attacks the electrophilic carbonyl carbon of an aldehyde or ketone. Protonation of the resulting alkoxide forms the β-hydroxy aldehyde or ketone product. The reaction can join two different aldehydes or ketones in a crossed-aldol condensation that expands the synthetic possibilities.
The document discusses carbonyl compounds, which contain a carbonyl group (C=O). This includes aldehydes, ketones, carboxylic acids, amides, and acid chlorides. It describes the structure of the carbonyl group and how the C=O double bond is polarized towards oxygen. This polarization allows carbonyl compounds to undergo nucleophilic addition reactions. Aldehydes are generally more reactive than ketones for electronic and steric reasons. Examples of reactions include hydration, cyanohydrin formation, imine formation, acetal formation, oxidation, reduction, and Friedel-Crafts acylation. Qualitative tests and important carbonyl compounds and their uses are also outlined.
The document discusses electrophilic aromatic substitution reactions of benzene and its derivatives. Key points include:
1) Benzene undergoes electrophilic substitution reactions that retain the aromatic ring structure. Common substitutions include halogenation, nitration, sulfonation, and Friedel-Crafts alkylation/acylation.
2) Electrophilic reactants are polarized by Lewis acids to attack the benzene π-system. Substitution occurs via a short-lived carbocation intermediate.
3) The electronic effects of substituents on the benzene ring determine the reaction orientation (ortho, meta, para). Activating groups donate electron density while deactivating groups withdraw electron density
The Wittig reaction converts aldehydes and ketones to alkenes using phosphorous ylides. A ylide is a molecule with adjacent opposite charges that is prepared from alkyl halides and triphenylphosphene. The ylide attacks the carbonyl carbon of an aldehyde or ketone to form a betaine intermediate. Betaine then eliminates triphenylphosphine oxide to generate the alkene product. For example, acetone reacts with a ylide to form 2-methylpropene.
The document discusses various aromatic electrophilic substitution reactions including Vilsmeier-Haack formylation, Reimer-Tiemann reaction, Gattermann-Koch formylation, and Kolbe-Schmitt reaction. It provides details on the reaction conditions, mechanisms, substrates used, and products formed for each reaction. It also discusses some exceptions and problems related to these reactions.
In organic chemistry, a carbonyl group is a functional group composed of a carbon atom double-bonded to an oxygen atom: C=O. It is common to several classes of organic compounds, as part of many larger functional groups. A compound containing a carbonyl group is often referred to as a carbonyl compound.
The document discusses the Cannizzaro reaction, which is the disproportionation of aldehydes in basic conditions to produce an alcohol and a carboxylic acid. It was discovered by Stanislao Cannizzaro in 1853. The reaction requires an aromatic or aliphatic aldehyde without alpha hydrogens and a strong base like potassium hydroxide. The mechanism involves deprotonation of the aldehyde followed by hydride transfer to another aldehyde molecule. Examples and limitations of the reaction are provided. Variations like the crossed and intramolecular Cannizzaro reactions are also described.
This is Power Point Presentation on Topic "Electrophilic Aromatic Substitution Reactions" as per syllabus of "University of Mumbai" for S.Y. B. Pharmacy (Sem.: IV) students.
1. The document discusses various electrophilic addition reactions that can occur with alkenes, including addition of bromine, hydrogen bromide, water, peroxyacids to form epoxides, borane to form alcohols, mercury acetate for oxymercuration-demercuration, and ozone for ozonolysis.
2. Key aspects of the reactions are discussed, including reaction mechanisms and products obtained via Markovnikov or anti-Markovnikov addition.
3. Examples are provided for many of the addition reactions to illustrate how different functional groups are formed depending on the reagents used.
The aldol condensation reaction involves the reaction of two carbonyl compounds in the presence of a strong base to form a β-hydroxyaldehyde or β-hydroxyketone. The reaction proceeds through the formation of an enolate ion intermediate that acts as a nucleophile, attacking the carbonyl carbon of the other molecule. This forms a carbon-carbon bond between the α-carbon of the donor molecule and the carbonyl carbon of the acceptor molecule. The aldol condensation reaction is useful for synthesizing larger molecules from simple starting materials and plays an important role in biochemical processes such as gluconeogenesis.
The document provides information on various types of condensation reactions, including aldol condensation, Claisen condensation, Knoevenagel condensation, benzoin condensation, and crossed aldol condensation. It discusses the mechanisms of these reactions, which involve a nucleophilic species (enolate or active hydrogen compound) attacking a carbonyl carbon to form a new carbon-carbon bond and water. Common reactants include esters, aldehydes, ketones, and acids or bases to catalyze enolate formation. Condensation reactions are important in biological processes like peptide bond formation and fatty acid biosynthesis.
Condensation reactions involve the combination of two molecules with the loss of a small molecule like water. Aldol condensation forms carbon-carbon bonds by reacting an enolate ion with a carbonyl compound. It plays a role in gluconeogenesis, photosynthesis, and producing perfumes. Other condensation reactions discussed include Claisen, Knoevenagel, Schiff base formation, and Dieckmann cyclization. Condensation polymers are formed through condensation reactions and examples include nylon and DNA. Condensation reactions are widely used in organic synthesis and producing pharmaceuticals, fragrances, and polymers.
The benzoin condensation is a reaction between two molecules of benzaldehyde catalyzed by cyanide ions to form benzoin. It was first reported in 1832 by Liebig and Wöhler. It involves a cyanide ion forming a cyanohydrin intermediate with benzaldehyde, followed by a condensation reaction between the cyanohydrin and another benzaldehyde molecule. This forms benzoin along with the removal of cyanide ions. Benzoin condensation is useful for organic synthesis and producing polymers.
The document discusses elimination reactions of alkyl halides. It begins by defining elimination reactions as those that involve the loss of elements from a starting material to form a new pi bond in the product. Specifically, it focuses on dehydrohalogenation reactions, where removal of HX occurs. The most common mechanism is E2 elimination, which is a bimolecular reaction promoted by a strong base. It follows second-order kinetics and has a single transition state. The document discusses characteristics of E2 reactions like Saytzeff's rule, Markovnikov's rule, anti-Markovnikov reactions, stereochemistry and stereoselectivity.
Electrophilic substitution reactions involve replacing a hydrogen atom in an aromatic ring with an electrophilic group such as nitro, halogen, sulfonic acid or alkyl/acyl groups. This is done using electrophiles generated in situ with a Lewis acid catalyst. It proceeds by generation of an electrophile, formation of a carbocation intermediate through attack on the aromatic ring, and removal of a proton. Ortho/para directing groups activate the ring towards substitution at those positions, while meta directing groups deactivate the ring at ortho/para positions. Polynuclear aromatic hydrocarbons with more than two fused benzene rings can be carcinogenic if inhaled from incomplete combustion.
The Perkin reaction is an organic reaction that produces α,β-unsaturated aromatic acids by condensing an aromatic aldehyde with an aliphatic acid anhydride in the presence of a weak base. The reaction was first discovered by William Henry Perkin in 1868. It involves the removal of water through condensation and produces the desired unsaturated carboxylic acid. Some examples of the Perkin reaction include converting furfural to furylacrylic acid, forming coumaric acid from salicylaldehyde which can then be dehydrated to coumarin, and synthesizing the phytoestrogenic compound resveratrol.
The aldol condensation reaction allows carbonyl compounds containing an α-hydrogen atom to undergo condensation. It is a reversible reaction that proceeds through an enolate intermediate formed when hydroxide deprotonates the α-hydrogen. The enolate then acts as a nucleophile that attacks the electrophilic carbonyl carbon of an aldehyde or ketone. Protonation of the resulting alkoxide forms the β-hydroxy aldehyde or ketone product. The reaction can join two different aldehydes or ketones in a crossed-aldol condensation that expands the synthetic possibilities.
The document discusses carbonyl compounds, which contain a carbonyl group (C=O). This includes aldehydes, ketones, carboxylic acids, amides, and acid chlorides. It describes the structure of the carbonyl group and how the C=O double bond is polarized towards oxygen. This polarization allows carbonyl compounds to undergo nucleophilic addition reactions. Aldehydes are generally more reactive than ketones for electronic and steric reasons. Examples of reactions include hydration, cyanohydrin formation, imine formation, acetal formation, oxidation, reduction, and Friedel-Crafts acylation. Qualitative tests and important carbonyl compounds and their uses are also outlined.
The document discusses electrophilic aromatic substitution reactions of benzene and its derivatives. Key points include:
1) Benzene undergoes electrophilic substitution reactions that retain the aromatic ring structure. Common substitutions include halogenation, nitration, sulfonation, and Friedel-Crafts alkylation/acylation.
2) Electrophilic reactants are polarized by Lewis acids to attack the benzene π-system. Substitution occurs via a short-lived carbocation intermediate.
3) The electronic effects of substituents on the benzene ring determine the reaction orientation (ortho, meta, para). Activating groups donate electron density while deactivating groups withdraw electron density
The Wittig reaction converts aldehydes and ketones to alkenes using phosphorous ylides. A ylide is a molecule with adjacent opposite charges that is prepared from alkyl halides and triphenylphosphene. The ylide attacks the carbonyl carbon of an aldehyde or ketone to form a betaine intermediate. Betaine then eliminates triphenylphosphine oxide to generate the alkene product. For example, acetone reacts with a ylide to form 2-methylpropene.
The document discusses various aromatic electrophilic substitution reactions including Vilsmeier-Haack formylation, Reimer-Tiemann reaction, Gattermann-Koch formylation, and Kolbe-Schmitt reaction. It provides details on the reaction conditions, mechanisms, substrates used, and products formed for each reaction. It also discusses some exceptions and problems related to these reactions.
In organic chemistry, a carbonyl group is a functional group composed of a carbon atom double-bonded to an oxygen atom: C=O. It is common to several classes of organic compounds, as part of many larger functional groups. A compound containing a carbonyl group is often referred to as a carbonyl compound.
The document discusses the Cannizzaro reaction, which is the disproportionation of aldehydes in basic conditions to produce an alcohol and a carboxylic acid. It was discovered by Stanislao Cannizzaro in 1853. The reaction requires an aromatic or aliphatic aldehyde without alpha hydrogens and a strong base like potassium hydroxide. The mechanism involves deprotonation of the aldehyde followed by hydride transfer to another aldehyde molecule. Examples and limitations of the reaction are provided. Variations like the crossed and intramolecular Cannizzaro reactions are also described.
This is Power Point Presentation on Topic "Electrophilic Aromatic Substitution Reactions" as per syllabus of "University of Mumbai" for S.Y. B. Pharmacy (Sem.: IV) students.
1. The document discusses various electrophilic addition reactions that can occur with alkenes, including addition of bromine, hydrogen bromide, water, peroxyacids to form epoxides, borane to form alcohols, mercury acetate for oxymercuration-demercuration, and ozone for ozonolysis.
2. Key aspects of the reactions are discussed, including reaction mechanisms and products obtained via Markovnikov or anti-Markovnikov addition.
3. Examples are provided for many of the addition reactions to illustrate how different functional groups are formed depending on the reagents used.
The aldol condensation reaction involves the reaction of two carbonyl compounds in the presence of a strong base to form a β-hydroxyaldehyde or β-hydroxyketone. The reaction proceeds through the formation of an enolate ion intermediate that acts as a nucleophile, attacking the carbonyl carbon of the other molecule. This forms a carbon-carbon bond between the α-carbon of the donor molecule and the carbonyl carbon of the acceptor molecule. The aldol condensation reaction is useful for synthesizing larger molecules from simple starting materials and plays an important role in biochemical processes such as gluconeogenesis.
The document provides information on various types of condensation reactions, including aldol condensation, Claisen condensation, Knoevenagel condensation, benzoin condensation, and crossed aldol condensation. It discusses the mechanisms of these reactions, which involve a nucleophilic species (enolate or active hydrogen compound) attacking a carbonyl carbon to form a new carbon-carbon bond and water. Common reactants include esters, aldehydes, ketones, and acids or bases to catalyze enolate formation. Condensation reactions are important in biological processes like peptide bond formation and fatty acid biosynthesis.
Condensation reactions involve the combination of two molecules with the loss of a small molecule like water. Aldol condensation forms carbon-carbon bonds by reacting an enolate ion with a carbonyl compound. It plays a role in gluconeogenesis, photosynthesis, and producing perfumes. Other condensation reactions discussed include Claisen, Knoevenagel, Schiff base formation, and Dieckmann cyclization. Condensation polymers are formed through condensation reactions and examples include nylon and DNA. Condensation reactions are widely used in organic synthesis and producing pharmaceuticals, fragrances, and polymers.
The Cannizzaro reaction, named after its discoverer Stanislao Cannizzaro, is a chemical reaction that involves the base-induced disproportionation of two molecules of a non-enolizable aldehyde to give a primary alcohol and a carboxylic acid
In organic chemistry, a carbonyl group is a functional group composed of a carbon atom double-bonded to an oxygen atom: C=O.
Method of preparation of Aldehyde and Ketone
Aldehydes and ketones contain a carbonyl group (>C=O) and can undergo numerous reactions. In aldehydes, the carbonyl is bonded to one alkyl group and one hydrogen. In ketones, it is bonded to two alkyl groups. Common reactions include reduction to alcohols using LiAlH4 or NaBH4, addition of Grignard reagents, and reactions involving the acidic alpha-hydrogens like benzoin condensation, Cannizzaro reaction, and Clemmenson reduction. Other important reactions are the Wittig reaction, Knoevenagel condensation, Wolf-Kishner reduction, and Baeyer-Villiger oxidation.
The document discusses reactions involving carbocation, carbene, and radical intermediates. It covers topics such as carbon-carbon bond formation reactions involving carbocations, rearrangements of carbocations, fragmentation reactions, the structure and reactivity of carbenes, generation of carbenes, addition and insertion reactions of carbenes, generation and reactions of ylides by carbene decomposition, rearrangement reactions of carbenes, and reactions involving nitrene and related intermediates. The document provides detailed mechanistic explanations and examples of many organic reactions that proceed through these reactive intermediate species.
The Arndt-Eistert homologation is a three step process that converts a carboxylic acid into its homologous acid (with one additional CH2 group) via an α-diazo ketone. It involves the conversion of the acid to an acid chloride using thionyl chloride, then displacement of the chloride with diazomethane to form the diazo ketone. The key step is the Wolff rearrangement of the diazo ketone catalyzed by silver to form a ketene intermediate that reacts with a nucleophile to form the homologated acid. It is a flexible and scalable method for chain elongation of carboxylic acids and their derivatives.
Baeyer Villiger Oxidation of Ketones, Cannizzaro Reaction, MPVADITYA ARYA
The document summarizes several organic chemistry reactions:
1) The Baeyer-Villiger oxidation reaction involves the oxidation of ketones with peroxy acids to form esters through a rearrangement reaction.
2) The Cannizzaro reaction involves the base-induced disproportionation of two aldehyde molecules to form a carboxylic acid and primary alcohol.
3) The Meerwein-Ponndorf-Verley (MPV) reduction uses aluminum isopropoxide catalyst in isopropanol to reduce aldehydes and ketones to the corresponding alcohols through a reversible reaction.
Chemical reactions_aldehyde and ketones.pptxNIDHI GUPTA
The document discusses carbonyl compound reactions, specifically the benzoin condensation and Perkin condensation. The benzoin condensation involves the dimerization of two aromatic aldehydes using a cyanide ion catalyst to form an aromatic acyloin compound like benzoin. The reaction mechanism involves nucleophilic addition of the cyanide ion to one aldehyde, followed by rearrangement and addition to the second aldehyde producing benzoin after proton transfer and cyanide elimination. The Perkin condensation is also discussed but no details are provided.
The document summarizes various reactions of aldehydes and ketones. It describes how aldehydes and ketones undergo nucleophilic addition reactions, with the nucleophile attacking the carbonyl carbon. This forms an alkoxide intermediate which gives an alcohol upon protonation. It also discusses the relative reactivities of aldehydes and ketones, hydrate and cyanohydrin formation, imine formation, oxidation and reductions of carbonyl compounds, acetal formation, and the Wittig reaction.
This document is a chemistry project on aldehydes, ketones, and carboxylic acids. It includes a certificate verifying completion, acknowledgements, index, and 5 sections discussing topics like nomenclature, preparation methods, reactions, and inductive effects. The project was assigned by a teacher and completed by a 12th grade student to fulfill an academic requirement. It provides an overview of key concepts regarding these functional groups in an educational format.
The document describes the strategy and key steps of solid phase peptide synthesis using the Merrifield method. In this method, the C-terminus of the first amino acid is attached to an insoluble polystyrene resin support. Subsequent amino acids are then added step-wise through repetition of deprotecting the N-terminus, coupling with the next protected amino acid, and further deprotection until the full peptide is synthesized while still attached to the resin. The final peptide is then cleaved off the resin support to obtain the pure peptide product.
This document discusses various aldol condensation reactions and their mechanisms. It introduces crossed aldol condensation which produces up to four products from two different carbonyl compounds. Self-aldol condensation uses a single aldehyde or ketone. Intramolecular aldol condensation occurs when a molecule contains two carbonyl groups. Several industrial reactions are also summarized, including the Aldox process, Perkin reaction, and Meerwein-Ponndorf-Verley reaction. In conclusion, these reactions are reversible and complete conversion can be achieved through excess alcohol or acetone removal.
The document summarizes the Darzen condensation reaction, which involves the formation of α,β-epoxy esters (glycidic esters) from aldehydes/ketones and α-halo esters under basic conditions. It provides background on the reaction's history and development. The reaction mechanism proceeds through an initial aldol reaction followed by epoxide ring formation. Examples and applications in multi-step syntheses are described. Limitations include the reaction failing for some aldehydes due to self-condensation and difficultly obtaining high, sole product yields needed for kinetic studies.
This document summarizes the rearrangement of benzilic acid from benzil. It introduces benzilic acid and notes that it can be prepared through rearrangement of the 1,2-α-diketone benzil. The document then outlines the preparation of benzil, the rearrangement mechanism involving nucleophilic addition and migration, and properties of the resulting benzilic acid including its white crystalline structure and solubility in alcohols. Hazards of benzilic acid are also mentioned, noting it is very hazardous if in contact with skin or eyes or if ingested or inhaled, and that it is chemically stable under recommended storage conditions.
The document summarizes the aldol condensation reaction of benzaldehyde and acetone to produce dibenzalacetone. It involves generating the acetone enolate ion using a strong base. The enolate then reacts with benzaldehyde through an E1CB mechanism to form the product. The reaction is performed in water/ethanol with sodium hydroxide and produces the trans, trans isomer of dibenzalacetone as the exclusive product. Stirring and controlling temperature and base concentration are important for obtaining the desired product.
Selenium dioxide (SeO2) and Raney nickel are both useful reagents in organic synthesis. SeO2 can be used to oxidize alkenes to allylic alcohols or carbonyls. It also oxidizes carbonyls to 1,2-dicarbonyls and internal alkynes to 1,2-dicarbonyls. Raney nickel catalyzes hydrogenation of aromatics and reduction of carbonyl groups by cleaving C-S bonds. Both reagents have applications in functional group transformations.
Alkenes are unsaturated hydrocarbons that contain at least one carbon-carbon double bond. They have the general formula CnH2n. Some key properties of alkenes include being less dense than alkanes and having boiling points that increase with molecular weight. Alkenes undergo addition reactions, such as adding halogens, hydrogen halides, hydrogen, and water across the double bond. The addition occurs according to Markovnikov's rule, where the negative part of the additive joins to the carbon with fewer hydrogen atoms. Alkenes can be prepared from alkynes, alkyl halides, and alcohols through reactions like reduction, dehydrohalogenation, and dehydration.
In 1891,Emil fischer devised a method of representing the 3D structures of
molecules in 2D Structures on a plane (Paper) by convention, horizontal line
represent bonds projecting from the plane of paper towards the observer and
vertical line represent away from the observer
Flash photolysis and Shock tube method PRUTHVIRAJ K
In 1967 the Nobel prize in chemistry was awarded to Manfred Eigen, Ronald George Wreyford Norrish for their co-discovery of Flash photolysis in 1949.
Flash photolysis is used to extensively to study reactions that happen extremely quickly, even down to the femtosecond depending on the laser that is used. The technique was born out of cameras developed during and shorty after WWII, which were used to take pictures of fast moving planes, rockets and Missiles.
Since then the technology of laser and optics has progressed allowing faster and faster reactions to be studied.
A silicate is an anions consisting of silicon and oxygen.
Silicates occur in earth’s crust in abundantly in the form of silicate minerals and aluminosilicate clay.
Silicate anions are often large polymeric molecules with an extense variety of structures,including chains and rings.double chains and sheets.
Silicates are extremely important materials, both natural and artificial, for all sorts of technological and artistic activities.
FUNCTIONAL GROUP MODIFICATION : Medicinal ChemistryPRUTHVIRAJ K
Once a lead compound or a pharmacophore structure with the desired pharmacological effect has been identified, organic chemists can introduce modifications in the chemical structure of the lead compound with the goal of improving the pharmacokinetics or pharmacodynamics of a drug candidate. These evolved structures are known as analogs.
3
IDENTIFICATION OF ACTIVE PART : THE PHARMACOPHOREPRUTHVIRAJ K
Portion of the molecule containing the essential organic functional groups that directly interact with the receptor active site and are responsible for the activity are know as pharmacophore.
Pharmacophore model represents the binding mode of active molecules to their target.
A pharmacophore model differentiates between active and inactive molecule.
STRUCTURE MODIFICATION TO INCREASE POTENCY AND THERAPEUTIC INDEX PRUTHVIRAJ K
1. It is a tool of research in medicinal chemistry to refine molecule.
2.Most of the molecules are modified either by altering its physical properties or by modifying chemical structure.
Structure modification is chemical alteration of known and previously characterized.
lead compound for the purpose of enhancing its usefulness as a drug (to improve activity).
This could mean enhancing its specificity for a particular body target site, increasing its potency.
Examples:
Progesterone and estradiol among the sex hormones
Nucleophilic Substitution reaction (SN1 reaction)PRUTHVIRAJ K
Attack of nucleophile at a saturated carbon atom bearing substituent, known as leaving group results in Substitution reaction.
The group that is displaced (leaving group) carries its bonding electrons.
The new bond is formed between nucleophile and the carbon using the electrons supplied by the nucleophilic agent.
The compound on which substitution takes place is called “substrate.”
The substrate consists of two parts, alkyl group and leaving group.
UNIMOLECULAR SURFACE REACTION: MECHANISM, INHIBITION AND ACTIVATION ENERGYPRUTHVIRAJ K
Unimolecular surface reaction may involve a reaction between a molecule A of the reactant and vacant site S on the surface
Surface reaction involving single adsorbed molecules and therefore term as unimolecular and are treated by Langmuir adsorption isotherm
Kinetics of Pyrolysis of acetaldehyde PRUTHVIRAJ K
Jeevankumar M presented a seminar on the pyrolysis of acetaldehyde under the guidance of Mr. Pruthviraj. Pyrolysis is the thermal degradation of compounds in the absence of oxygen above the boiling point of water. The pyrolysis of acetaldehyde occurs through a chain reaction, producing methyl radicals and hydrogen. The mechanism involves initiation, propagation, and termination steps. Applying steady-state approximations, the rate law for the pyrolysis of acetaldehyde was determined to be third order with respect to acetaldehyde concentration. Pyrolysis has applications in producing fuels from waste and in industrial processes like steelmaking and syngas production.
Diel's-Alder and Gattermann Koch ReactionsPRUTHVIRAJ K
n organic chemistry, the Diels–Alder reaction is a chemical reaction between a conjugated diene and a substituted alkene, commonly termed the dienophile, to form a substituted cyclohexene derivative. It is the prototypical example of a pericyclic reaction with a concerted mechanism
The Chichibabin reaction is a method for producing 2-aminopyridine derivatives by the reaction of pyridine with sodium amide. It was reported by Aleksei Chichibabin in 1914. The following is the overall form of the general reaction: The direct amination of pyridine with sodium amide takes place in liquid ammonia
Pigments and Colors: Natural Pigments or Plant Pigments PRUTHVIRAJ K
Biological pigments, also known simply as pigments or biochromes, are substances produced by living organisms that have a color resulting from selective color absorption. Biological pigments include plant pigments and flower pigment
The document discusses different types of food colourants. It describes natural food colourants that are synthesized naturally, nature-identical colourants that are synthesized to mimic natural ones, and artificial/synthetic colourants. Seven synthetic colours are approved by the FDA for food use. Natural colours come from vegetable, animal, mineral or other sources. Carotenoids provide yellow, orange and red colours and have health benefits. Beta-carotene is an important carotenoid used as a food colourant. Betalains and chlorophylls are also used as natural food colourants. Anthoxanthins contribute cream and white colours while lycopene provides the red colour of tomatoes.
The document discusses chirality in heteroatom systems where chirality arises from a non-carbon centre. It explains that compounds containing nitrogen, phosphorus, sulfur or other atoms can exhibit stereochemistry when the atom forms a tetrahedral structure with four different groups. The stereochemistry of these compounds provides useful information for drug applications. It then focuses on the specific stereochemistry of various nitrogen, phosphorus and sulfur compounds, including amines, oximes, azo compounds, phosphines and sulfoxides. It describes how these compounds can exhibit geometrical isomers, inversion barriers, and retention or inversion of configuration under chemical reactions.
Conformational analysis of medium ringsPRUTHVIRAJ K
The document discusses the conformations of medium-sized carbocyclic rings from cycloheptane to cyclodecane. Cycloheptane exists in two sets of conformers, with the preferred conformers being twist-chair. Medium rings from cyclooctane to cyclodecane exhibit unusual features like intraannular and extraannular hydrogens leading to transannular strain. Cyclodecane preferentially adopts a boat-chair-boat conformation to minimize these interactions. Pseudorotation in these rings can be slowed by introducing substituents that restrict bond rotation.
Pigments and Colors:Extraction and PurificationPRUTHVIRAJ K
Pigments and Colors:Extraction and Purification- Extraction of naturally occurring pigments like anthocyanins, tannins etc from their sources and purification methods
The document discusses helicity and chirality in organic chemistry. It explains that helicity arises in molecules with a helical shape, which are inherently chiral. It also describes how overcrowding in molecules like helicenes can lead to helicity. The document then discusses asymmetric synthesis and how existing chiral centers induce asymmetric induction to form diastereomers in unequal amounts. It presents Cram's rule and Prelog's rule as methods to predict the configuration of the predominant diastereomer based on the existing chiral centers.
Executive Directors Chat Leveraging AI for Diversity, Equity, and InclusionTechSoup
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How to Manage Your Lost Opportunities in Odoo 17 CRMCeline George
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Physiology and chemistry of skin and pigmentation, hairs, scalp, lips and nail, Cleansing cream, Lotions, Face powders, Face packs, Lipsticks, Bath products, soaps and baby product,
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A review of the growth of the Israel Genealogy Research Association Database Collection for the last 12 months. Our collection is now passed the 3 million mark and still growing. See which archives have contributed the most. See the different types of records we have, and which years have had records added. You can also see what we have for the future.
This presentation includes basic of PCOS their pathology and treatment and also Ayurveda correlation of PCOS and Ayurvedic line of treatment mentioned in classics.
ISO/IEC 27001, ISO/IEC 42001, and GDPR: Best Practices for Implementation and...PECB
Denis is a dynamic and results-driven Chief Information Officer (CIO) with a distinguished career spanning information systems analysis and technical project management. With a proven track record of spearheading the design and delivery of cutting-edge Information Management solutions, he has consistently elevated business operations, streamlined reporting functions, and maximized process efficiency.
Certified as an ISO/IEC 27001: Information Security Management Systems (ISMS) Lead Implementer, Data Protection Officer, and Cyber Risks Analyst, Denis brings a heightened focus on data security, privacy, and cyber resilience to every endeavor.
His expertise extends across a diverse spectrum of reporting, database, and web development applications, underpinned by an exceptional grasp of data storage and virtualization technologies. His proficiency in application testing, database administration, and data cleansing ensures seamless execution of complex projects.
What sets Denis apart is his comprehensive understanding of Business and Systems Analysis technologies, honed through involvement in all phases of the Software Development Lifecycle (SDLC). From meticulous requirements gathering to precise analysis, innovative design, rigorous development, thorough testing, and successful implementation, he has consistently delivered exceptional results.
Throughout his career, he has taken on multifaceted roles, from leading technical project management teams to owning solutions that drive operational excellence. His conscientious and proactive approach is unwavering, whether he is working independently or collaboratively within a team. His ability to connect with colleagues on a personal level underscores his commitment to fostering a harmonious and productive workplace environment.
Date: May 29, 2024
Tags: Information Security, ISO/IEC 27001, ISO/IEC 42001, Artificial Intelligence, GDPR
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1. NAMED REACTIONS IN ORGANIC
SYNTHESIS: Benzoin Condensation
By
PRUTHVIRAJ K
PRUTHVIRAJ K, MSc
2. Benzoin Condensation.
• Upon treating certain (but not all) aromatic aldehydes or glyoxals (α-keto
aldehydes) with cyanide ion (CN-), benzoins (α-hydroxy-ketones or acyloins)
are produced in a reaction called the benzoin condensation. The reverse
process is called the retro-benzoin condensation, and it is frequently used for
the preparation of ketones. The condensation involves the addition of one
molecule of aldehyde to the C=O group of another. One of the aldehydes
serves as the donor and the other serves as the acceptor. Some aldehydes
can only be donors (e.g.pdimethylaminobenzaldehyde) or acceptors, so they
are not able to self-condense, while other aldehydes (benzaldehyde) can
perform both functions and are capable of self-condensation. Certain
thiazolium salts can also catalyze the reaction in the presence of a mild
base.
• his version of the benzoin condensation is more synthetically useful than
the original procedure because it works with enolizable and non-enolizable
aldehydes and asymmetric catalysts may be used. Aliphatic aldehydes can
also be used and mixtures of aliphatic and aromatic aldehydes give mixed
benzoins. Recently, it was also shown that thiazolium-ion based organic
ionic liquids (OILs) promote the benzoin condensation in the presence of
small amounts of triethylamine.12 The stereoselective synthesis of benzoins
has been achieved using chiral thiazolium salts as catalysts.
PRUTHVIRAJ K, MSc
3. Mechanism
All the steps of the cyanide ion catalyzed benzoin condensation are
completely reversible, and the widely accepted mechanism involves
the loss of the aldehydic proton in the key step. This deprotonation
is possible due to the increased acidity of this C-H bond caused by
the electron-withdrawing effect of the CN group. The cyanide ion is
a very specific catalyst of the reaction. Cyanide is a good
nucleophile, a good leaving group, and its electronwithdrawing
effect enhances the acidity of the aldehyde hydrogen.
PRUTHVIRAJ K, MSc
5. Synthetic applications
A. Miyashita and co-workers have developed a new method for the synthesis of ketones based on the
concept that the benzoin condensation is reversible (retro-benzoin condensation) and affords the most
stable product. When α- benzylbenzoin was treated with KCN in DMF, the C-C bond was cleaved,
resulting in the formation of deoxybenzoin and benzaldehyde. This method of synthesizing ketones has
been applied to several α-substituted benzoins, and the corresponding ketones were formed in good
yields. The authors also realized, based on the known analogy between the chemical behavior of the
C=O double bond of ketones and the C=N double bond of nitrogen-containing heteroarenes, that a
cyanide ion catalyzed retro-benzoin condensation of α-hydroxybenzylheteroarenes would also be possible
The retro-benzoin condensation methodology was used to synthesize 2-substituted quinazolines in good
overall yield from 2,4-dichloroquinazoline. 2-Substituted quinazolines are obtained by substitution of 2-
chloroquinazoline with nucleophiles, though it is difficult to prepare the starting 2-chloroquinazoline.
These results indicate that the aroyl group, which may be introduced onto nitrogen-containing
heteroarenes at the α-position, can be used as a protecting group. Later it can be easily removed by
conversion to an α-hydroxybenzyl group, followed by a retro-benzoin condensation.
PRUTHVIRAJ K, MSc
6. • In the laboratory of K. Suzuki, a catalytic crossed aldehyde-ketone benzoin condensation was
developed and applied to the synthesis of stereochemically defined functionalized
preanthraquinones.
PRUTHVIRAJ K, MSc
7. REFERENCES
• STRATEGIC APPLICATIONS OF NAMED REACTIONS IN
ORGANIC SYNTHESIS
By- Laszlo Kurti and Barbara Czako
• REACTIONS, REARRANGEMNTS AND REAGENTS
By- S N Sanyal
PRUTHVIRAJ K, MSc