Active Methylene Compounds MCQs [Organic Chemistry]

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1. : Malonic ester can be used to prepare which of the following?
(A) Carboxylic acids
(B) Amino acids
(C) Keto acids
(D) All A, B, and C

2. : What is the order of percentage enolic character of malonic ester (I), acetoacetic ester (II) and cyanoacetic ester (III)?
3. : For preparation of various monocarboxylic acids malonic ester hydrolysis is treated with which of the following?
(A) NaO C2H5
(B) Na/C2H5OH
(C) NaO C2H5
(D) RX

4. : What is formed when Malonic ester reacts with urea in presence of POCl₃?
(A) Parabamic acid
(B) Barbituric acid
(C) Veronal
(D) Luminal

5. : In its synthetic applications, cyanoacetic ester closely resembles
(A) Ethyl acetoacetate
(B) Acetoacetic ester
(C) Nitroacetic ester
(D) Malonic ester

6. : The compound with which cyanoacetic ester can react but malonic ester cannot is
(A) Acetone
(B) Acetaldehyde
(C) Acid halide
(D) Alkyl halide

7. : The reaction used for the preparation of ethyl acetoacetate starting from ethyl acetate is known as
(A) Cannizzaro reaction
(B) Claisen condensation
(C) Michael condensation
(D) Claisen-Schmidt reaction

8. : The enolic form of acetoacetic ester as compared to ketonic form contains:
(A) One extra lone pair
(B) One extra double bond
(C) One less double bond
(D) Both have same number of σ, π bonds and lone pairs

9. : Why does keto-enol tautomerism arise?
(A) Due to migration of enolic group
(B) Due to migration of a keto group
(C) Due to migration of a proton
(D) Due to migration of hydroxyl group

10. : Which is true regarding tautomers?
(A) Tautomers must have dynamic equilibrium between functional isomers
(B) Tautomers must have same functional group
(C) Tautomers must have same position of double bond
(D) Tautomers must have static equilibrium between functional isomers

11. : What is the order of enolic contents of CH₃COCH₂COOC₂H₅(I), CH₃COCH₂COCH₃(II) and CH₃COCH₃CHO(III)?
12. : ___________ is not a reaction of enolic form of acetoacetic ester.
(A) Coloration with FeCl₃
(B) Addition of bromine
(C) Acetylation
(D) Reaction with HCN

13. : Ethyl acetoacetate when boiled with aqueous KOH undergoes hydrolysis to form mainly:
(A) CH₃COCH₂COOH
(B) CH₃COOH
(C) CH₃COCH₃
(D) CH₃COCOOH

14. : Which is formed after reaction of ethyl acetoacetate with phenyl hydrazine?
(A) Methyl isoxazolone
(B) Methyl isoxapyrazolone
(C) 3-Methyl-1-phenylpyrazolone
(D) Dimethyl phenyl oxazolone

15. : Ethyl acetoacetate may be used to prepare:
(A) Ketonic acids
(B) Ketones
(C) Carboxylic acids
(D) All A, B, and C

16. : Which of the following can be formed by reaction of sodium ethoxide with malonic ester?
(A) Resonance stabilized free radical
(B) Resonance stabilized cation
(C) Resonance stabilized anion
(D) Resonance stabilized electrophile

17. : Succinic acid may be obtained from sodium malonic ester by its reaction with ______ followed by hydrolysis.
(A) R–X
(B) Dil. HCl
(C) Alc. KOH
(D) I₂

18. : A reactive methylene group is a methylene group present between what kind of groups?
(A) Electron donating groups
(B) Carbonyl groups
(C) Hydroxyl groups
(D) Amino groups

19. : Which is not a reactive methylene compound?
(A) CH₃COCH₂COOC₂H₅
(B) C₂H₅OOCCH₂CH₂CN
(C) C₂H₅OOCCH₂COOC₂H₅
(D) C₂H₅OOCCH₂CH₂NH₂

20. : Which is the compound that exhibits keto-enol tautomerism?
(A) C₂H₅OOCCH₂COCH₃
(B) C₂H₅OOCCH₂NO₂
(C) C₂H₅OOCCH₂CN
(D) C₂H₅OOCCH₂CH₃

Active Methylene Compounds MCQs [Organic Chemistry]
By: Prof. Dr. Fazal Rehman | Last updated: May 23, 2025

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