Organic Chemistry Exam 4 MC LATEST QUESTIONS AND 100- Verified ANSWERS.

Organic Chemistry Exam 4 MC LATEST
QUESTIONS AND 100- Verified ANSWERS.

Organic Chemistry Exam 4 – Multiple Choice
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1. Which of the following is the most enolizable carbonyl compound?
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a) Acetone
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b) Benzaldehyde
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c) Methyl acetate
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d) N,N-Dimethylacetamide
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2. The Claisen condensation of ethyl acetate produces:
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a) Ethyl acetoacetate
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b) Ethyl acetate dimer
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c) Ethyl 3-oxobutanoate
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d) Both a and c
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3. In the Michael addition, a nucleophile adds to:
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a) An α,β-unsaturated carbonyl compound at the β-carbon
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b) An aldehyde carbonyl carbon
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c) An epoxide ring
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d) A nitrile group
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4. Which reagent is commonly used to reduce an ester to a primary alcohol without affecting a
bn bn bn bn bn bn bn bn bn bn bn bn bn bn bn bn b




carbon-carbon double bond?
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a) LiAlH₄
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b) NaBH₄
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c) DIBAL-H at low temperature
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d) H₂/Pd-C
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5. A Wittig reaction between benzyltriphenylphosphonium chloride and cyclohexanone yields:
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a) Cyclohexylmethanol
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b) Methylenecyclohexane
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c) Benzylidenecyclohexane
bn




d) Cyclohexyl benzoate
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6. Which of the following amines is most basic in aqueous solution?
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a) Aniline
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b) Cyclohexylamine
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,c) Pyrrole
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d) Acetamide
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7. The product of a Hofmann elimination of a quaternary ammonium hydroxide derived from a
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primary amine is:
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a) A tertiary amine
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b) An alkene (least substituted)
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c) An alkene (most substituted)
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d) An alcohol
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8. The carbohydrate D-glucose and D-mannose are:
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a) Enantiomers
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b) Epimers at C-2
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c) Epimers at C-4
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d) Anomers
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9. Which test would distinguish an aldopentose from a ketohexose?
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a) Iodine test
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b) Seliwanoff’s test
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c) Biuret test
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d) 2,4-DNP test
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10. The [4+2] cycloaddition reaction is known as:
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a) Claisen rearrangement
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b) Diels–Alder reaction
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c) Cope rearrangement
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d) Electrocyclic reaction
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11. Which of the following dienes is most reactive in a Diels–
bn bn bn bn bn bn bn bn bn bn bn




Alder reaction with maleic anhydride?
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a) 1,3-Butadiene
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b) 2-Methyl-1,3-butadiene (isoprene)
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c) 1,3-Cyclohexadiene
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d) 1-Phenyl-1,3-butadiene
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12. The Cope rearrangement of 1,5-hexadiene proceeds through:
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a) A radical intermediate
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b) A charged intermediate
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c) A concerted pericyclic transition state
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d) A carbene intermediate
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13. In the ¹H NMR spectrum of ethyl acetoacetate (keto form), the methylene group adjacent t
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o both carbonyls appears as:
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a) A singlet
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, b) A doublet
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c) A triplet
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d) A quartet
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14. Which compound will show a strong absorption around 1720 cm⁻¹ and another around 250
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0–3500 cm⁻¹ (broad) in IR? bn bn bn bn




a) Ethyl benzoate
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b) Benzoic acid
bn bn




c) Benzaldehyde
bn




d) Benzophenone
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15. A compound has molecular formula C₄H₈O₂. Its IR shows a strong peak at 1735 cm⁻¹. Its ¹H
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NMR has a triplet at 1.2 ppm (3H), a quartet at 4.1 ppm (2H), and a singlet at 2.0 ppm (3H). Th
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e compound is:
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a) Butanoic acid
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b) Ethyl acetate
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c) Methyl propanoate
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d) 2-Butanone
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16. Reduction of a nitrile with LiAlH₄ yields:
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a) A primary amine
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b) A secondary amine
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c) An aldehyde
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d) An imine
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17. The Gabriel synthesis is used to prepare:
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a) Aromatic aldehydes
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b) Primary amines from alkyl halides
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c) β-Keto esters
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d) α-Amino acids
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18. Which of the following enamines, upon hydrolysis, gives back a ketone?
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a) Enamine from pyrrolidine and cyclohexanone
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b) Enamine from aniline and acetone
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c) Enamine from piperidine and benzaldehyde
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d) All of the above
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19. The stereochemistry of the Diels–Alder adduct is typically:
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a) Racemic
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b) Syn addition with respect to diene and dienophile
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c) Anti addition
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d) Dependent on solvent polarity
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