Question 1

Which of the following carbonyl-containing compounds is the most reactive toward nucleophilic addition, according to the reactivity trend shown in the study materials?

Accepted Answer

Aldehyde ($$RCHO)$$

Question 2

Which reagent and conditions would you use to selectively reduce an ester to an aldehyde without further reduction to an alcohol?

Accepted Answer

1. $$\mathrm{DIBAL}$$, $$-70^\circ \mathrm{C}$$; 2. $$\mathrm{H_2O}$$

Question 3

Which of the following statements best describes the difference between kinetic and thermodynamic enolate formation?

Accepted Answer

Kinetic enolates form faster and are less substituted, while thermodynamic enolates are more substituted and more stable.

Question 4

Which protecting group would be most appropriate to protect an amide nitrogen during a reaction with a strong nucleophile?

Accepted Answer

Boc (tert-butoxycarbonyl)

Question 5

Which of the following best explains why OsO$$_4$$ and KMnO$$_4/$$NaOH both convert alkenes to diols, but with different yields?

Accepted Answer

OsO$$_4 is a $$milder oxidant and gives higher yields of syn-diols.

Question 6

Which of the following statements about the Fischer indole synthesis is correct?

Accepted Answer

It involves the reaction of a phenylhydrazine with an aldehyde or ketone.

Question 7

Which of the following is a key feature of the Shikimate pathway in primary metabolism?

Accepted Answer

It provides precursors for aromatic amino acids.

Question 8

Which of the following best describes the role of protecting groups in organic synthesis?

Accepted Answer

They temporarily mask functional groups to prevent unwanted reactions.

Question 9

Which of the following statements about pyridine is FALSE?

Accepted Answer

The lone pair on nitrogen is delocalized in the aromatic system.

Question 10

Which of the following best explains why electrophilic aromatic substitution in pyrrole occurs under milder conditions than in benzene?

Accepted Answer

Pyrrole is more nucleophilic due to the electron-donating effect of the nitrogen atom.

Question 11

Which of the following is a correct statement about the reactivity of diazines compared to pyridine?

Accepted Answer

Diazines are less reactive toward electrophilic substitution and more reactive toward nucleophilic substitution.

Question 12

Which of the following best describes the difference between primary and secondary metabolism?

Accepted Answer

Primary metabolism is essential for cell survival, while secondary metabolism produces non-essential small molecules.

Question 13

Which of the following is a key consideration when choosing a protecting group for a synthesis?

Accepted Answer

The protecting group should be easily added and removed under conditions that do not affect other functional groups.

Question 14

Which of the following best explains why the Wittig reaction is important in organic synthesis?

Accepted Answer

It allows for the selective formation of alkenes from carbonyl compounds.

Question 15

Which of the following statements about the stability of alkenes is correct?

Accepted Answer

Alkene stability increases with conjugation and hyperconjugation.

Question 16

Which of the following is a correct statement about the reactivity of quinolines and isoquinolines?

Accepted Answer

Electrophilic aromatic substitution occurs on the benzenoid ring, while nucleophilic substitution occurs on the pyridine ring.

Question 17

Which of the following best describes the outcome of using $$n-$$BuLi versus LDA in enolate formation?

Accepted Answer

$$n-$$BuLi is less selective and can lead to side reactions, while LDA is more selective for enolate formation.

Question 18

Which of the following is a key feature of aromatic heterocycles that distinguishes them from carbocyclic aromatics?

Accepted Answer

They contain a heteroatom that contributes to the delocalized $$\pi-$$system.

Question 19

Which of the following best explains why furan is more reactive than thiophene in electrophilic aromatic substitution?

Accepted Answer

The oxygen atom in furan donates electron density more effectively than sulfur in thiophene.

Advanced Organic Chemistry: Reactivity, Synthesis, and Heterocycles

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