NEETChemistryAldehydes and Ketones
Match List-I with List-II regarding the total number of structurally distinct aldol condensation products (including both self and cross products, but excluding stereoisomers) formed when the given pairs of carbonyl compounds are heated with dilute NaOH . List-I (Reactants) List-II (Total products) (A) Ethanal + Propanal (I) 0 (B) Propanone + Pentan-2-one (II) 2 (C) Benzaldehyde + Acetophenone (III) 4 (D) Formaldehyd
Options
- A(A)-(III), (B)-(IV), (C)-(II), (D)-(I)
- B(A)-(II), (B)-(IV), (C)-(III), (D)-(I)
- C(A)-(IV), (B)-(III), (C)-(II), (D)-(I)
- D(A)-(III), (B)-(II), (C)-(IV), (D)-(I)
Correct answer
A. (A)-(III), (B)-(IV), (C)-(II), (D)-(I)
Step-by-step solution
The number of aldol products depends on the number of distinct enolates that can form and the number of electrophilic carbonyl carbons available. (A) Ethanal has 1 type of -hydrogen and Propanal has 1 type. Total products = 1 (self-ethanal) + 1 (self-propanal) + 2 (cross) = 4. (B) Propanone has 1 type of -hydrogen. Pentan-2-one has 2 types of -hydrogens ( C ₁ and C ₃ ), thus forming two different enolates. Total products = 1 (self-propanone) + 2 (self-pentan-2-one) + 3 (cross products: propanone enolate with pentan