Q 1 :

m-chlorobenzaldehyde on treatment with 50% KOH solution yields                 [2024]

Q 2 :

Given below are two statements:                                                                                             [2024]

Statement I: Acidity of $\mathrm{\alpha }$-hydrogens of aldehydes and ketones is responsible for Aldol reaction.

Statement II: Reaction between benzaldehyde and ethanal will NOT give Cross – Aldol product.

In the light of the above statements, choose the most appropriate answer from the options given below.

[Aldol Condensation Reaction]

• Statement I is incorrect but Statement II is correct.

   

• Statement I is correct but Statement II is incorrect.

   

• Both Statement I and Statement II are correct.

   

• Both Statement I and Statement II are incorrect.

   

Q 3 :

Two moles of benzaldehyde and one mole of acetone under alkaline conditions using aqueous NaOH after heating gives $\mathrm{x}$ as the major product. The number of $\pi$ bonds in the product $\mathrm{x}$ is _______.                [2024]

Q 4 :

The major product of the following reaction is :             [2025]

${\mathrm{CH}}_3{\mathrm{CH}}_2\mathrm{CH}=\mathrm{O}\underset{\mathrm{reflux}}{\overset{\text{excess HСНО alkali}}{\to }}?$

• 

   

• 

   

• 

   

• ${\mathrm{CH}}_3-{\mathrm{CH}}_2-{\mathrm{CH}}_2-\mathrm{OH}$

   

Q 5 :

A man has been asked to synthesise the molecule  (x). He thought of preparing the molecule using an aldol condensation reaction. He found a few cyclic alkenes in his laboratory. He thought of performing ozonolysis reaction on alkene to produce a dicarbonyl compound followed by aldol reaction to prepare “x”. Predict the suitable alkene that can lead to the formation of “x”.            [2025]

Q 6 :

Aldol condensation is a popular and classical method to prepare $\mathrm{\alpha },\mathrm{\beta }$-unsaturated carbonyl compounds. This reaction can be both intermolecular and intramolecular. Predict which one of the following is not a product of intramolecular aldol condensation?            [2025]

Q 7 :

When 

undergoes intramolecular aldol condensation, the major product formed is :           [2025]

Q 8 :

Compound (X) undergoes the following sequence of reactions to give the lactone (Y).               [2023]

Q 9 :

Consider the following reaction

$\text{Propanal}+\text{Methanal}$$\underset{\begin{array}{c}\text{(ii) }\Delta \\ \text{(iii) NaOH}\\ {\text{(iv) H}}_3{\mathrm{O}}^{+}\end{array}}{\overset{\text{(i) dil. NaOH}}{\to }}\underset{({\mathrm{C}}_5{\text{H}}_8{\text{O}}_3\text{)}}{\text{Product B}}$

The correct statement for product B is. It is                  [2023]

• Optically active and adds one mole of bromine

   

• Optically active alcohol and is neutral

   

• Racemix mixture and gives a gas with saturated ${\mathrm{NaHCO}}_3$ solution

   

• Racemix mixture and is neutral

   

Q 10 :

A in the above reaction is:                    [2023]

Q 11 :

Given below are two statements:                                   [2026]

Statement I: Cross aldol condensation between two different aldehydes will always produce four different products.

Statement II: When semicarbazide reacts with a mixture of benzaldehyde and acetophenone under optimum pH, it forms a condensation product with acetophenone only.

In the light of the above statements, choose the correct answer from the options given below:

• Both Statement I and Statement II are true

   

• Both Statement I and Statement II are false

   

• Statement I is true but Statement II is false

   

• Statement I is false but Statement II is true

   

Q 12 :

The compound A, ${\mathrm{C}}_8{\mathrm{H}}_8{\mathrm{O}}_2$ reacts with acetophenone to form a single product via cross-Aldol condensation. The compound A on reaction with conc. NaOH forms a substituted benzyl alcohol as one of the two products. The compound A is :    [2026]

• 4-hydroxy benzylaldehyde

   

• 4-methoxy benzaldehyde

   

• 4-methyl benzoic acid

   

• 2-hydroxy acetophenone