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 greater partial positive charge on the carbonyl carbon compared to ketones.

Question 2

What is the product when propanal ($$\mathrm{CH_3CH_2CHO}) $$reacts with methylmagnesium bromide ($$\mathrm{CH_3MgBr}) $$followed by acid workup?

Accepted Answer

$$\mathrm{CH_3CH_2CH(OH)CH_3$} (2-$$butanol)

Question 3

Which reagent would selectively reduce an ester to an aldehyde without further reduction to an alcohol?

Accepted Answer

DIBALH ($$\mathrm{(iBu)_2AlH}) at$$ $$-78^\circC$$

Question 4

Which of the following compounds is the most reactive toward nucleophilic addition?

Accepted Answer

Formaldehyde ($$\mathrm{H_2CO})$$

Question 5

A chemist wants to synthesize 3-hexanone from 1-propanol. Which sequence of reactions would achieve this transformation?

Accepted Answer

Oxidation to propanal, Grignard addition of ethylmagnesium bromide, then oxidation

Question 6

Which of the following best describes the product of the reaction between an aldehyde and a primary amine under mildly acidic conditions?

Accepted Answer

An imine ($$\mathrm{C=NR})$$

Question 7

What is the major product when 2-pentanone reacts with ethylmagnesium bromide ($$\mathrm{C_2H_5MgBr}) $$followed by acid workup?

Accepted Answer

3-methyl-3-hexanol

Question 8

Which of the following statements about the reduction of carboxylic acids with $$\mathrm{$$LiAlH_4$$} is $$correct?

Accepted Answer

The carboxylic acid is reduced all the way to a primary alcohol.

Question 9

Which of the following best explains why the equilibrium constant for hydrate formation is highest for formaldehyde?

Accepted Answer

Formaldehyde is less sterically hindered and its carbonyl carbon is more electrophilic.

Question 10

Which product is formed when an acyl chloride reacts with a Grignard reagent in excess, followed by acid workup?

Accepted Answer

A tertiary alcohol

Question 11

What is the outcome when an aldehyde reacts with sodium cyanide ($$\mathrm{NaCN}) $$and hydrochloric acid?

Accepted Answer

A cyanohydrin is formed

Question 12

Which of the following reagents would reduce an amide to an amine?

Accepted Answer

$$\mathrm{$$LiAlH_4$$}$$

Question 13

Which of the following is a correct statement about the Wittig reaction?

Accepted Answer

It forms an alkene from a carbonyl compound and a phosphonium ylide.

Question 14

Which of the following best describes the selectivity of organocuprates ($$\mathrm{R_2CuLi}) in $$reactions with acyl chlorides?

Accepted Answer

They add once to form a ketone.

Question 15

Which of the following is true regarding the reaction of aldehydes and ketones with water?

Accepted Answer

The reaction forms a hydrate, and the equilibrium favors the hydrate more for formaldehyde than for acetone.

Question 16

Which of the following best describes the product of the reaction between an aldehyde and two equivalents of an alcohol under acidic conditions?

Accepted Answer

An acetal

Question 17

Which of the following statements about the reduction of carbonyl compounds is correct?

Accepted Answer

Catalytic hydrogenation can reduce both carbon–carbon and carbon–oxygen double bonds.

Question 18

Which of the following is the correct IUPAC name for the compound with the structure $$\mathrm{CH_3CH=CHCH_2CHO}$$?

Accepted Answer

3-pentenal

Question 19

Which of the following best describes the chemoselectivity of DIBALH?

Accepted Answer

It selectively reduces esters to aldehydes at low temperature.

Reactions of Aldehydes and Ketones & More Reactions of Carboxylic Acid Derivatives

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