Aldol condensation ● Aldehydes and ketones with at least one 𝞪-hydrogen undergo a reaction in the presence of dilute alkali as catalyst. Aldol condensation (or aldol reaction) Mechanism Shortcut for aldol reaction [JEE MAIN 2022] In the given reaction (X) and (Y) will respectively be : Intramolecular aldol condensation ● 6 > 5 > 7 > 4 > 3 membered ring formation (Stability) ● Attack on Aldehyde group preferred over Ketone (B) major product (B) is A. B. C. D. The major product obtained in the following reaction is [2019] A. B. C. D. In the scheme given below, the total number of intramolecular aldol condensation products formed from ‘Y’ is [IIT 2010] Cross Aldol Reaction Cross Aldol Reaction The major product obtained in the following reaction is [JEE MAIN 2019] Cannizzaro Reaction Aldehyde having no α - hydrogens in the presence of conc. NaOH/Δ or KOH/Δ, undergo self oxidation and reduction (disproportionation) reaction on heating with concentrated alkali.undergo disproportionation reaction Mechanism [JEE MAIN 2022] Which of the following will not undergo Cannizzaro reaction A. B. C. D. Cannizaro’s reaction is not given by A. C. CH3CHO B. D. HCHO JEE MAIN [2013] Cross cannizzaro Reaction Major products of the following reaction are [ JEE MAIN 2019] A. B. C. D. Identify A in the following chemical reaction A. B. C. D. JEE MAIN [2021] Intramolecular Cannizzaro reaction ● Here two carbonyl groups (without α-hydrogen atom) are present within the same molecule. Intramolecular Cannizzaro reaction Haloform Reaction or Haloform Test Aldehydes and ketones having at least one methyl group linked to the carbonyl carbon atom (methyl ketones) are oxidised by sodium/potassium hypohalite (NaOX) to sodium/potassium salts of corresponding carboxylic acids having one carbon atom less than that of carbonyl compound. Haloform Reaction or Haloform Test Haloform Reaction or Haloform Test Alcohol that convert to methyl ketone also give positive haloform test The major products formed in the following reaction sequence A and B are JEE MAIN 2021 A. B. C. D. The structure of the starting compound P used in the reaction given below is JEE MAIN 2021 A. B. C. D. Consider the given reaction, the product ‘X’ is JEE MAIN 2021 A. B. C. D. Hoffmann’s Bromamide Reaction Mechanism Hoffmann’s Bromamide Reaction ● Only 1º Amide can show this reaction, 2º and 3º amides do not show this reaction ● Overall 4 unit of base are consumed ● Alkyl group with better migrating aptitude show relatively faster reaction. ● There is retention of configuration during rearrangement. A. B. C. D. Esterification Reaction ● Any reaction in which ester is formed is known as esterification [JEE MAIN 2022] Intramolecular esterification Hell–volhard–Zelinisky (HVZ) reaction ● In the presence of a small amount of red phosphorus, aliphatic carboxylic acids react smoothly with chlorine or bromine to yield a compound in which α-hydrogen has been replaced by halogen. [JEE Main 2022] A. B. C. D. In the presence of a small amount of phosphorous, aliphatic carboxylic acids react with chlorine or bromine to yield a compound in which alphahydrogen has been replaced by halogen. This reaction is known as A. Wolff-Kishner reaction B. Etard reaction C. Hell-Volhard-Zelinsky reaction D. Rosenmund reaction [JEE Main 2015] Clemmensen reduction Wolff-Kishner Reduction Rosenmund reduction Stephen reduction DiBAL-H Reduction Gatterman – Koch reaction Etards Reaction Chromyl chloride (CrO2Cl2 ) oxidises methyl group to a chromium complex, which on hydrolysis gives corresponding benzaldehyde. [JEE MAIN 2022] Heating Effect Decarboxylation reactions: Soda Lime On heating carboxylic acids with soda-lime (NaOH and CaO), an alkane is obtained with one carbon less than the carboxylic acid Heating Effect Mechanism : ● Electron withdrawing group at R–COOH will increases the rate of decarboxylation. Heating of β-keto acids ● β-keto acids decarboxylate readily when they are heated to 100–150ºC. ● When the acid itself decarboxylates, it can do so through a six membered cyclic transition state : The total number of carboxylic acid groups in the product P is ______. [JEE Advanced 2013] The compound that undergoes decarboxylation most readily under mild condition is : [JEE Advance 2012] A. B. C. D. Decarboxylation reactions ● Malonic Acid Anhydride formation 1, 4 and 1, 5-dibasic acid undergo intramolecular dehydration to give cyclic anhydrides. Anhydride formation 1, 4 and 1, 5-dibasic acid undergo intramolecular dehydration to give cyclic anhydrides. Anhydride formation Anhydride formation Gabriel phthalimide Reaction ● Primary Alkyl Halide converts to primary amines ● Primary amine is obtained in good yield Mechanism A. B. C. D. B. D. Phthalimide Preparation Carbene and its Preparation Carbylamine Reaction/Isocyanide Test ● Aliphatic and aromatic primary amines on heating with CHCI3 + KOH form isocyanides or carbylamines Carbylamine Reaction/Isocyanide Test ● Isocyanides are foul smelling substances. ● Secondary and tertiary amines do not show this reaction. ● It is a test for primary amines. Mechanism The major product obtained in the following reaction is A. B. C. D. [2021] A. B. C. D. Reimer-Tiemann Reaction Reimer-Tiemann Reaction Step (I) Step (II) attack of :CCl2 is the slow step (i.e. rate determining step) The intermediate X, in the reaction A. B. C. D. [JEE MAIN 2022] The electrophile involved in the above reaction is A. B. C. D. Trichloromethyl anion Formyl cation Phenoxide ion dichlorocarbene [2018] Reimer-Tiemann carboxylation reaction Kolbe Schmitt reaction Diazonium salt and Reaction Diazotization The major product formed in the reaction given below will be JEE MAIN [2019] A. B. C. D. Reactions of (Benzenediazoniumchloride) Reactions of (Benzenediazoniumchloride) In the following reaction sequence, [C] is [2020] A. B. C. D. Coupling reactions Diazonium salts undergo coupling reactions with phenols, 𝛃-naphthols and aromatic amines to form highly coloured azo-compounds. Coupling reactions with Phenol and Aniline Mechanism Coupling reactions with 𝛃-napthol (Red dye) Mechanism [JEE MAIN 2022] A. B. C. D. In the following reactions, the major product W is JEE Advance [2015] A. B. C. D. Wurtz reaction ● When alkyl halide reacts with Sodium in presence of dry ether to give alkane Wurtz reaction Fittig reaction ● When aryl halide reacts with Sodium in presence of dry ether Wurtz Fittig reaction ● When aryl halide and Alkyl halide reacts with Sodium in presence of dry ether Kolbe's Electrolysis ● Alkanes are formed on electrolysis of concentrated aqueous solution of sodium or potassium salt of saturated monocarboxylic acids. ● Reaction follows ionic and free radical mechanism. Kolbe's Electrolysis Mechanism Photohalogenation Aromatization Aromatization 3. The number of -CH2- (methylene) groups in the product formed from the following reaction sequence is ________ Electrophilic Aromatic Substitutions (EAS) Reaction ● Substitution of an electrophile for a proton on the aromatic ring so it is called electrophilic aromatic substitution. Mechanism Electrophilic Aromatic Substitutions - Effect of Substituent Groups Friedel Craft Alkylation When benzene is treated with an alkyl halide in the presence of anhydrous AlCl3, alkylbenene is formed. Friedel Craft Alkylation Intramolecular Friedel Craft Alkylation Friedel Craft Alkylation in Aniline and Phenol Friedel Craft Acylation Reaction Acylation of benzene may be brought about with acid chlorides or anhydrides in presence of Lewis acids. Friedel Craft Acylation Reaction Friedel Craft Acylation Reaction Nitration Nitration of Phenol Nitration of Aniline Sulphonation The replacement of a hydrogen atom by a sulphonic acid (SO3H) group in a ring is called sulphonation Desulphonation Halogenation Arenes react with halogens in the presence of a Lewis acid like anhydrous FeCl3 , FeBr3 or AlCl3 to yield haloarenes. AA. AB AC AD Halogenation of Phenol (a) When the reaction is carried out in solvents of low polarity such as CHCl3 or CS2 and at low temperature, monobromo phenols are formed. Halogenation of Phenol (b) When phenol is treated with bromine water, 2,4,6-tribromophenol is formed as white precipitate. Halogenation of Aniline Halogenation Electrophilic Addition Reaction Markownikoff's Rule When molecule of HX add up on unsymmetrical unsaturated hydrocarbon, the electrophile (H+) goes to the unsaturated carbon atom bearing more number of hydrogen atoms. The major product in the following reaction [JEE MAIN 2022] A. B. C. D. The major product ‘Y’ in the following reaction is JEE Main [2019] A. B. C. D. Ozonolysis Reaction Ozonolysis Reaction Final product is/are A. B. C. D. Kucherov’s Reaction Finkelstein Reaction (SN2) Finkelstein Reaction (SN2) Major product of the reaction is A. B. C. D. Swarts Reaction (SN2) Williamson Ether Synthesis (SN2) Identify (Y) A. B. C. D. None of these SNAr: Nucleophilic Aromatic Substitution This is the characteristic reaction of aryl halides with ortho or para electron withdrawing substituent. Cl OH- SNAr: Nucleophilic Aromatic Substitution General Mechanism for SNAr Important Points for SNAr Important Points for SNAr The electron-withdrawing substituent must be ortho or para to the site of nucleophilic attack SN i Reaction (Darzen’s process) In the SNi mechanism (substitution nucleophilic internal), a part of the leaving group must be able to attack the substrate. SN i Reaction tinyurl.com/PlayJEE Daily Hits! tinyurl.com/PlayJEE Telegram Channel t.me/livejee Bratin Mondal Amaiya Singhal 100 %ile 100 %ile LIVE Class Environment LIVE Polls & Leaderboard LIVE Doubt Solving LIVE Interaction Performance Analysis Weekly Test Series DPPs & Quizzes India’s BEST Educators Class 11 JEE 2024 Unacademy Subscription Droppers JEE 2023 If you want to be the BEST “Learn” from the BEST Class 12 JEE 2023 Plus ICONIC 11th / 9, 10 extra 11th / 9, 10 12th / Drop 12th / Drop UDAAN UDAAN Use Code: UDAAN UDAAN UDAAN
