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Aldol, Cannizzaro, Perkin, Claisen and related condensations

55 questions on Aldol, Cannizzaro, Perkin, Claisen and related condensations from the Aldehydes, Ketones and Carboxylic Acids chapter: 11 NEET level, 22 JEE Main, 22 JEE Advanced. Each one opens with its answer and solution.

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Ethanal is treated with cold dilute aqueous NaOH. The aldol addition product formed is NEET level
Which of the following undergoes the Cannizzaro reaction on heating with concentrated NaOH? NEET level
Benzaldehyde is heated with ethanoic anhydride and sodium ethanoate, and the mixture is then acidified. The main product (Perkin reaction) is NEET level
The number of alpha-hydrogen atoms in propanone, CH3COCH3, is NEET level
Ethyl ethanoate is treated with one equivalent of sodium ethoxide in ethanol and then acidified. The Claisen condensation product is NEET level
3-Hydroxybutanal is warmed with dilute acid. The product formed by loss of water is NEET level
Benzaldehyde is warmed with aqueous-alcoholic KCN. The product of this benzoin condensation is NEET level
Acetophenone (C6H5COCH3) and benzaldehyde are warmed with NaOH in ethanol until dehydration is complete (Claisen-Schmidt condensation). The product is NEET level
Which of the following cannot form an enolate and therefore cannot act as the nucleophile in an aldol reaction? NEET level
Benzaldehyde reacts with diethyl propanedioate (diethyl malonate) in the presence of a catalytic amount of piperidine (Knoevenagel condensation). The product is NEET level
Benzaldehyde is treated with concentrated NaOH at room temperature. The products formed are NEET level
Equimolar methanal and benzaldehyde are treated with concentrated NaOH (crossed Cannizzaro reaction). Before acidification, the products are JEE Main level
Ethanedial, OHC-CHO, is heated with concentrated NaOH and the mixture is then acidified. The organic product is JEE Main level
Phenylglyoxal, C6H5COCHO, is treated with concentrated NaOH and the mixture is then acidified. The product is JEE Main level
Hexane-2,5-dione, CH3COCH2CH2COCH3, is heated with dilute NaOH (intramolecular aldol condensation). The product is JEE Main level
Hexanedial, OHC(CH2)4CHO, is treated with dilute NaOH and warmed so that the intramolecular aldol product dehydrates. The product is JEE Main level
Heptane-2,6-dione, CH3CO(CH2)3COCH3, is heated with dilute NaOH. The intramolecular aldol condensation product is JEE Main level
Benzaldehyde (1 mol) is added to excess propanone with dilute NaOH and warmed until dehydration is complete (Claisen-Schmidt condensation). The main product is JEE Main level
Diethyl hexanedioate is treated with one equivalent of NaOEt in ethanol and the mixture is then acidified (Dieckmann condensation). The product is JEE Main level
Assertion (A): When methanal and benzaldehyde react in concentrated NaOH, phenylmethanol and sodium methanoate are formed. Reason (R): Methanal is more electrop... JEE Main level
Ethyl benzoate and ethyl ethanoate are treated with NaOEt, with ethyl ethanoate added slowly to the mixture of ethyl benzoate and base (crossed Claisen condensa... JEE Main level
The total number of alpha-hydrogens in 2-methylcyclohexanone (the methyl group is on the ring carbon next to C=O) is JEE Main level
Each pair of carbonyl compounds below is mixed with dilute NaOH at low temperature. Counting only aldol addition products (no dehydration, ignoring stereoisomer... JEE Main level
Ethanal is heated with a catalytic amount of aluminium ethoxide in dry benzene (Tishchenko reaction). The product is JEE Main level
Propanone is treated with BrCH2COOC2H5 and zinc in dry ether, followed by mild aqueous acid work-up (Reformatsky reaction). The product is JEE Main level
But-3-en-2-one, CH2=CHCOCH3, reacts with diethyl propanedioate in the presence of a catalytic amount of NaOEt (Michael addition). The 1,4-adduct is JEE Main level
Cyclohexanone is treated with but-3-en-2-one and base. The overall transformation (Robinson annulation) proceeds as JEE Main level
In the benzoin condensation catalysed by cyanide, the key role of CN^- is JEE Main level
Ethanal and 2,2-dimethylpropanal are mixed in the presence of dilute NaOH at low temperature (no dehydration). The main crossed aldol addition product is JEE Main level
Which of the following undergo the Cannizzaro reaction on heating with concentrated NaOH? (One or more answers) JEE Main level
Which of the following cannot act as the enolate (nucleophile) component in an aldol reaction? (One or more answers) JEE Main level
Ethyl ethanoate undergoes Claisen condensation with sodium ethoxide in ethanol. Which statements are correct? (One or more answers) JEE Main level
Benzaldehyde (31.8 g, molar mass 106 g mol^-1) is converted entirely by concentrated NaOH into phenylmethanol and sodium benzoate (Cannizzaro reaction). Phenylm... JEE Main level
Acetophenone and benzaldehyde are warmed with NaOH in ethanol until dehydration is complete to give P. P is then shaken with exactly one mole of H2 over Pd/C at... JEE Advanced level
Ethanal is warmed with dilute NaOH to give X. X is then hydrogenated with excess H2 over Ni at high pressure to give Y. Y is JEE Advanced level
Propanone with Ba(OH)2 gives P. P is warmed with a trace of iodine to give Q by loss of water. Q is treated with excess NaOCl (haloform reaction) and then acidi... JEE Advanced level
Ethanal is heated with excess methanal and Ca(OH)2. Three successive crossed aldol additions occur at the alpha carbon, and the resulting trihydroxy aldehyde is... JEE Advanced level
Ethyl 3-oxobutanoate (1 mol) reacts with but-3-en-2-one in the presence of NaOEt. The Michael adduct then undergoes an intramolecular aldol condensation with lo... JEE Advanced level
Diethyl heptanedioate is treated with one equivalent of NaOEt in ethanol (Dieckmann condensation). The product is then heated with dilute aqueous sulfuric acid,... JEE Advanced level
Ethyl ethanoate is treated with NaOEt (1 mol) and then acidified to give A. A is treated with NaOEt followed by C2H5Br to give B. B is warmed with dilute NaOH, ... JEE Advanced level
For 3-methylcyclohexanone (methyl on the ring carbon two positions from C=O), which option gives both the total number of alpha-hydrogens and the number of cons... JEE Advanced level
Benzaldehyde is heated with propanoic anhydride and sodium propanoate, and the mixture is then acidified. The main product is JEE Advanced level
Benzaldehyde is heated with propanedioic acid (malonic acid) in pyridine with a trace of piperidine (Knoevenagel-Doebner condensation). Which option correctly g... JEE Advanced level
Cyclohexanone is treated with BrCH2COOC2H5 and zinc in dry ether, followed by mild acid work-up to give P. P is warmed with aqueous NaOH, and the cooled mixture... JEE Advanced level
Cyclohexanone (1 mol) is treated with benzaldehyde (2 mol) and NaOH in ethanol until both condensations and dehydration are complete. The product is JEE Advanced level
Benzaldehyde is heated with aqueous-alcoholic KCN to give P. P is treated with NaBH4 in methanol (ketone reduction, then work-up) to give Q. Q is JEE Advanced level
Which of the following undergo an intramolecular Cannizzaro reaction (one carbonyl carbon is oxidised and another reduced within the same molecule) on treatment... JEE Advanced level
Which of the following combinations give an alpha,beta-unsaturated carbonyl compound by loss of one H2O when warmed with dilute NaOH? (One or more answers) JEE Advanced level
Which statements about the Cannizzaro reaction of benzaldehyde with concentrated NaOH are correct? (One or more answers) JEE Advanced level
Which diesters give a five- or six-membered cyclic beta-keto ester as the main product when treated with one equivalent of NaOEt in ethanol (Dieckmann condensat... JEE Advanced level
Which statements about the Reformatsky reaction are correct? (One or more answers) JEE Advanced level
Which compounds contain exactly four alpha-hydrogen atoms? (One or more answers) JEE Advanced level
With catalytic NaOEt in ethanol, which pairs of reactants undergo Michael (conjugate) addition? (One or more answers) JEE Advanced level
Which transformations form a six-membered ring as the new ring? (One or more answers) JEE Advanced level
Benzaldehyde (5.30 g, molar mass 106 g mol^-1) is converted into cinnamic acid by the Perkin reaction with an isolated yield of 64%. All of the cinnamic acid is... JEE Advanced level