Question 1

Which of the following statements best explains why aldehydes are generally more reactive toward nucleophilic addition than ketones?

Accepted Answer

Aldehydes have less steric hindrance and a more electrophilic carbonyl carbon due to only one alkyl group attached.

Question 2

What is the correct IUPAC name for the following compound: $$\mathrm{CH_3CH_2CH_2CHO}$$?

Accepted Answer

Butanal

Question 3

Which reagent would you use to selectively oxidize a primary alcohol to an aldehyde without further oxidation to a carboxylic acid?

Accepted Answer

$$\mathrm{PCC} ($$Pyridinium chlorochromate)

Question 4

Which of the following reactions will convert a terminal alkyne into an aldehyde?

Accepted Answer

1) $$\mathrm{R_2B-H}$$, 2) $$\mathrm{H_2O_2}$$, $$\mathrm{NaOH}$$

Question 5

A ketone reacts with two equivalents of ethanol under acidic conditions. What is the major organic product?

Accepted Answer

An acetal

Question 6

Which of the following best describes the mechanism of nucleophilic addition to a carbonyl group under basic conditions?

Accepted Answer

Nucleophilic attack occurs first, followed by protonation of the oxygen atom.

Question 7

Which of the following statements about acetal formation is correct?

Accepted Answer

Acetal formation from aldehydes or ketones is catalyzed by acid and is reversible.

Question 8

Which of the following is a correct statement about the hydrolysis of imines?

Accepted Answer

Hydrolysis of imines requires acidic conditions and produces a carbonyl compound and a primary amine.

Question 9

Which of the following is the product of the reaction between a ketone and $$\mathrm{HSCH_2CH_2SH}$$ under acidic conditions, followed by treatment with Raney Ni?

Accepted Answer

An alkane

Question 10

What is the major organic product when cyclohexanone reacts with a Wittig reagent ($$\mathrm{Ph_3P=CH_2$}$$)?

Accepted Answer

Cyclohexene

Question 11

Which of the following best describes the Baeyer-Villiger oxidation?

Accepted Answer

An oxygen atom is inserted between the carbonyl carbon and an adjacent group.

Question 12

Which of the following is a correct statement about the equilibrium between a ketone and its hydrate in water?

Accepted Answer

The equilibrium favors the hydrate more for formaldehyde than for acetone.

Question 13

Which of the following is the correct product of the reaction between a ketone and hydrogen cyanide ($$\mathrm{HCN}$$)?

Accepted Answer

A cyanohydrin

Question 14

Which of the following best explains why cyclic acetals are often used as protecting groups for carbonyl compounds in multi-step synthesis?

Accepted Answer

Cyclic acetals are stable under basic conditions and can be easily removed under acidic conditions.

Question 15

Which of the following is a key difference between the formation of imines and enamines from carbonyl compounds?

Accepted Answer

Imines are formed from primary amines, while enamines are formed from secondary amines.

Question 16

A student wants to convert a ketone to an alkane. Which sequence of reagents would achieve this transformation?

Accepted Answer

1) $$\mathrm{HSCH_2CH_2SH}$$, $$[H^+]$$; 2) Raney Ni

Question 17

Which of the following is the correct mechanism for the acid-catalyzed addition of water to a carbonyl compound?

Accepted Answer

Protonation of the carbonyl oxygen, nucleophilic attack by water, then deprotonation to form the hydrate.

Aldehydes and Ketones: Structure, Preparation, and Reactions

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