Cannizzaro reaction class 12

1. Acetylation: The replacement of active hydrogen of alcohols, phenols, amines or even benzene with acetyl group (CH 3CO -) is called acetylation. This is always carried out with acetoyl chloride, or acetic anhydride (CH 3CO) 2O. 2. Cannizzaro reaction: Aldehydes which do not contain an oc hydroges when treated with concentrated solution of an alkali undergo self oxidation reduction. As a result one molecule of aldehyde is reduced to corresponding alcohol while the other molecule is oxidised to the corresponding acid. This reaction is called Cannizzaro reaction. Aldehydes such as formaldehyde, benzaldehyde (C 6H 5CHO) which do not contain ∝ hydrogen undergo this reaction. 3. Cross aldol condensation: Condensation between 2 defferent aldehydes or ketones, at least one of which contains ∝ – hydrogen is called aldol condensation. It is a useful synthetic tool only when one of the aldehyde or ketone does not contains ∝ – hydrogen. This is because if both the aldehydes or ketones contain ∝ – hydrogen it gives a mixture of four different products. eg:Condensation between formaldehyde and acetaldehyde in the presence of dil NaOH (aq) 4. Decarboxylation:The process of removal of CO 2 from a carboxylic acid is called decarboxylation. It is generally carried out by heating the acid or its sodium salt with soda lime (NaOH + CaO) at 630 K. For eg:

Explain the following with one example: (a) Aldol condensation (b) Cannizzaro's reaction (c) Wolff-Kishner reduction (d) Rosenmund's reduction (e) Clemmensen'sreduction (t) Polymerisation (g) HaIoform reaction (h) Tischenko's reaction (i) Beckmann rearrangement 0) Meerwein-Ponndorf-Verley reduction (k) Pinacol-Pinacolone rearrangement (I) Refonnatsky reaction (m) Oppenauer oxidation (n) Claisen-Schmidt reaction

Hint: In chemistry, two types of compounds are organic and inorganic. Organic compounds that contain carbon-hydrogen bonds. Carbon has a high catenation property, due to it, there are many organic compounds available in nature. Complete answer: Acetylation - It is a type of chemical reaction that explains the acetyl functional group into a chemical compound. These compounds are also known as acetates or acetate esters. It has an opposite reaction that is known as Deacetylation. In this reaction, the acetyl group removes from the chemical compound. Cannizzaro reaction - It is a kind of chemical reaction that adds base-induced disproportionation of two molecules of non-enolizable aldehyde. It gives primary alcohol and carboxylic acid. It first came into the news in$1853$, when benzyl alcohol and potassium benzoate reacted. $2$ Note:Acetylation has another name according to IUPAC name that is Ethanoylation. Cannizzaro reaction name is based on the name of an Italian chemist that is Stanislao Cannizzaro. Aldol reaction happens in organic compounds because it provides a carbon-carbon bond.

(i) Acetylation Acetyl group is introduced in an organic compound. Reagent is acetyl chloride or acetic anhydride. Bases such as pyridine and dimethylaniline are used to neutralize acid (HCl or acetic acid). (ii) Cannizzaro reaction Aldehydes (not having alpha hydrogen atoms) undergo self oxidation-reduction (disproportionation) reaction. One molecule is oxidized to carboxylic acid and other molecule is reduced to alcohol. Concentrated alkali is the reagent. (iii) Cross aldol condensation Aldol condensation between different carbonyl compounds (aldehdyes and ketones). If both reactants contain alpha hydrogen atom, four different products can be obtained. (iv) Decarboxylation Loss of C O 2 ​ from carboxylic acids to form hydrocarbons. For this, sodium salts of carboxylic acids are heated with soda lime.

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Explain the following with one example: (a) Aldol condensation (b) Cannizzaro's reaction (c) Wolff-Kishner reduction (d) Rosenmund's reduction (e) Clemmensen'sreduction (t) Polymerisation (g) HaIoform reaction (h) Tischenko's reaction (i) Beckmann rearrangement 0) Meerwein-Ponndorf-Verley reduction (k) Pinacol-Pinacolone rearrangement (I) Refonnatsky reaction (m) Oppenauer oxidation (n) Claisen-Schmidt reaction

Hint: In chemistry, two types of compounds are organic and inorganic. Organic compounds that contain carbon-hydrogen bonds. Carbon has a high catenation property, due to it, there are many organic compounds available in nature. Complete answer: Acetylation - It is a type of chemical reaction that explains the acetyl functional group into a chemical compound. These compounds are also known as acetates or acetate esters. It has an opposite reaction that is known as Deacetylation. In this reaction, the acetyl group removes from the chemical compound. Cannizzaro reaction - It is a kind of chemical reaction that adds base-induced disproportionation of two molecules of non-enolizable aldehyde. It gives primary alcohol and carboxylic acid. It first came into the news in$1853$, when benzyl alcohol and potassium benzoate reacted. $2$ Note:Acetylation has another name according to IUPAC name that is Ethanoylation. Cannizzaro reaction name is based on the name of an Italian chemist that is Stanislao Cannizzaro. Aldol reaction happens in organic compounds because it provides a carbon-carbon bond.

(i) Acetylation Acetyl group is introduced in an organic compound. Reagent is acetyl chloride or acetic anhydride. Bases such as pyridine and dimethylaniline are used to neutralize acid (HCl or acetic acid). (ii) Cannizzaro reaction Aldehydes (not having alpha hydrogen atoms) undergo self oxidation-reduction (disproportionation) reaction. One molecule is oxidized to carboxylic acid and other molecule is reduced to alcohol. Concentrated alkali is the reagent. (iii) Cross aldol condensation Aldol condensation between different carbonyl compounds (aldehdyes and ketones). If both reactants contain alpha hydrogen atom, four different products can be obtained. (iv) Decarboxylation Loss of C O 2 ​ from carboxylic acids to form hydrocarbons. For this, sodium salts of carboxylic acids are heated with soda lime.

1. Acetylation: The replacement of active hydrogen of alcohols, phenols, amines or even benzene with acetyl group (CH 3CO -) is called acetylation. This is always carried out with acetoyl chloride, or acetic anhydride (CH 3CO) 2O. 2. Cannizzaro reaction: Aldehydes which do not contain an oc hydroges when treated with concentrated solution of an alkali undergo self oxidation reduction. As a result one molecule of aldehyde is reduced to corresponding alcohol while the other molecule is oxidised to the corresponding acid. This reaction is called Cannizzaro reaction. Aldehydes such as formaldehyde, benzaldehyde (C 6H 5CHO) which do not contain ∝ hydrogen undergo this reaction. 3. Cross aldol condensation: Condensation between 2 defferent aldehydes or ketones, at least one of which contains ∝ – hydrogen is called aldol condensation. It is a useful synthetic tool only when one of the aldehyde or ketone does not contains ∝ – hydrogen. This is because if both the aldehydes or ketones contain ∝ – hydrogen it gives a mixture of four different products. eg:Condensation between formaldehyde and acetaldehyde in the presence of dil NaOH (aq) 4. Decarboxylation:The process of removal of CO 2 from a carboxylic acid is called decarboxylation. It is generally carried out by heating the acid or its sodium salt with soda lime (NaOH + CaO) at 630 K. For eg:

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