Deck 18: Ketones and Aldehydes

Question 1

Another name for β-methoxybutyraldehyde is:

A) 2-methoxypropanal.
B) 3-methoxypropanal.
C) 2-methoxybutanal.
D) 3-methoxybutanal.
E) 2-methoxypentanal.

Answer 1

3-methoxybutanal.

Question 2

Provide the IUPAC name for (CH₃)₃CCH₂CHClCH₂CHO.

Answer 2

3-chloro-5,5-dimethylhexanal

Question 3

Provide the proper IUPAC name for CH₃OCH₂CH₂CH(CH₃)CHO.

Answer 3

4-methoxy-2-methylbutanal

Question 4

Name the following compound.

Question 5

Provide the structure of benzophenone.

Question 6

Give an IUPAC name to the following compound. Be sure to include configurational information in the name.

Question 7

Would you expect the carbonyl carbon of benzaldehyde to be more or less electrophilic than that of acetaldehyde? Explain using resonance structures.

Question 8

Provide the proper IUPAC name for CH₃CHBrCH₂COCH₂CHO.

Question 9

What is the correct IUPAC name for the following compound?

A) 2-oxocyclohex-3-ene carbaldehyde
B) 5-formylcyclohex-2-enone
C) 2-formylcyclohex-5-enone
D) 3-oxocyclohex-4-enal

Question 10

Provide the IUPAC name for the following compound.

Question 11

The double bond between carbon and oxygen is similar to an alkene C=C, except that C=O is:

A) shorter and weaker.
B) shorter and stronger.
C) longer and weaker.
D) longer and stronger.
E) longer.

Question 12

Which of the following correctly describes the bond angle and hybridizations present in formaldehyde?

A) C, sp²; O, sp³; HCO, ~120°
B) C, sp²; O, sp²; HCO, ~120°
C) C, sp²; O, sp²; HCO, ~109.5°
D) C, sp³; O, sp²; HCO, ~109.5°
E) C, sp³; O, sp³; HCO, ~109.5°

Question 13

Provide the proper IUPAC name for PhCH₂CH(CH₃)CH₂CH₂CHO.

Question 14

Provide the structure of 4-oxohexanoic acid.

Question 15

Draw the ethylene acetal of benzaldehyde.

Question 16

The positively polarized carbon atom of a carbonyl group acts as:

A) an electrophile and a Lewis base.
B) a nucleophile and a Lewis base.
C) an electrophile and a Lewis acid.
D) a nucleophile and a Lewis acid.
E) both a Lewis acid and a Lewis base.

Question 17

Name the following compound.

Question 18

Provide the structure of cyclohexanecarbaldehyde.

Question 19

Provide the proper IUPAC name for (CH₃)₂CHCH₂CH₂COCH=CH₂.

Question 20

Provide the proper IUPAC name for CH₃CHOHCH₂COCH₂C(CH₃)₂CH₂CH₃.

Question 21

Trioxane is a cyclic trimer of formaldehyde that can be converted to formaldehyde upon heating. Show this reaction.

Question 22

What reagent can be used to convert 2-methylbutan-1-ol into 2-methylbutanal?

A) LiAlH₄
B) Na₂Cr₂O₇
C) O₃
D) KMnO₄
E) PCC

Question 23

What reagents can be used to convert 1-hexyne into 2-hexanone?

A) 1. Sia₂BH; 2. H₂O₂, NaOH
B) Hg²⁺, H₂SO₄, H₂O
C) 1. O₃; 2. (CH₃)₂S
D) 1. CH₃MgBr; 2. CO₂
E) 1. H₂, Ni; 2. Na₂Cr₂O₇, H₂SO₄

Question 24

Provide the major organic product which results when PhCHO is treated with the following sequence of reagents:

Question 25

Which is more soluble in water, 2-butanone or n-hexane? Explain.

Question 26

Which compound will show an intense peak in the mass spectrum at m/z 58?

A) CH₃COCH₂CH₂CH₃
B) (CH₃)₂CHCOCH₃
C) CH₃CH₂COCH₂CH₃
D) (CH₃)₃CCHO
E) (CH₃)₃CCOCH₃

Question 27

In the proton NMR spectra of aldehydes and ketones, the protons bonded to carbons adjacent to the carbonyl group typically fall into which of the chemical shift ranges below?

A) 1.0-2.0 ppm
B) 2.0-3.0 ppm
C) 4.0-4.5 ppm
D) 7.0-8.0 ppm
E) 9.0-10.0 ppm

Question 28

Which of the following represents the correct ranking in terms of increasing boiling point?

A) n-butane < 1-butanol < diethyl ether < 2-butanone
B) n-butane < 2-butanone < diethyl ether < 1-butanol
C) 2-butanone < n-butane < diethyl ether < 1-butanol
D) n-butane < diethyl ether < 1-butanol < 2-butanone
E) n-butane < diethyl ether < 2-butanone < 1-butanol

Question 29

In carbon NMR, the carbon atom of the carbonyl group in aldehydes and ketones has a chemical shift of about:

A) 20 ppm.
B) 40 ppm.
C) 60 ppm.
D) 120 ppm.
E) 200 ppm.

Question 30

The strongest absorptions in the UV spectra of aldehydes and ketones are ones which result from ________ electronic transitions.

A) σ to σ^*
B) σ to π^*
C) n to π^*
D) π to π^*
E) π to σ^*

Question 31

Name the following compound.

Question 32

Which of the following compounds is most soluble in water?

A) acetone
B) cyclohexanone
C) 2-butanone
D) 3-butanone
E) benzophenone

Question 33

How might one distinguish an aldehyde from a ketone using IR data alone?

Question 34

Which of the following transitions is usually observed in the UV spectra of ketones?

A) n to π^*
B) n to π
C) σ to n
D) σ to σ^*
E) n to σ^*

Question 35

Which of the following compounds would show only one triplet in its off resonance decoupled ¹³C NMR spectrum?

A) acetone
B) butanal
C) pentanal
D) 2-pentanone
E) 3-pentanone

Question 36

The proton NMR spectrum of an unknown compound contains a triplet at 9.8 ppm. Which of the following could be this unknown?

A) (CH₃)₃CCHO
B) CH₃CH₂CH₂CO₂H
C) CH₃CH₂CH₂CHO
D) CH₃CO CH₂Ph
E) PhCHO

Question 37

What name is given to the linear polymer which contains many formaldehyde units?

A) trioxane
B) formalin
C) paraformaldehyde
D) polyacetaldehyde
E) polyalal

Question 38

When a carbonyl is part of a conjugated π-network, the C-O stretch:

A) has a higher frequency than in a nonconjugated system.
B) has a lower frequency than in a nonconjugated system.
C) always occurs at 1710 cm^-1.
D) occurs around 2700 cm^-1.
E) cannot be distinguished from the C-O stretch in a nonconjugated system.

Question 39

Provide the major organic product which results when PhCHOHCH₃ is treated with PCC.

Question 40

In the mass spectrum of 3,3-dimethyl-2-butanone, the base peak will occur at m/z ________.

A) 43
B) 58
C) 84
D) 85
E) 100

Question 41

Provide the major organic product which results when pentanal is subjected to the following sequence of steps:

Question 42

Provide the major organic product of the reaction shown below.

Question 43

By which single reaction can benzene be readily converted into acetophenone?

Question 44

Which of the following reactions $\underline{\text{ will not }}$ yield a ketone product?

A)

B)

C)

D)

E)

Question 45

Propose a synthesis of 3-heptanone from propanal.

Question 46

Complete the following reaction by filling in the correct reagents.

Question 47

Name the compound generated when ethylbenzene is treated with CO, HCl, AlCl₃, and CuCl.

Question 48

Beginning with sodium acetylide (NaCCH), propose a three-step synthesis of hexanal.

Question 49

Oxidation of a 1° alcohol with pyridinium chlorochromate results in the production of ________.

A) an ester
B) a ketone
C) an aldehyde
D) an ether
E) none of the above

Question 50

Which of the following describes a synthesis of an aldehyde?

A) hydrogenation of an acid chloride using Pd/BaSO₄/S as a poisoned catalyst
B) reaction of a primary alcohol with Na₂Cr₂O₇
C) reaction of a ketone with ozone
D) treatment of an alkene with Sia₂BH
E) none of the above

Question 51

Provide the major organic product which results when PhCH₂CH₂CO₂H is treated with excess butyllithium followed by H₃O⁺.

Question 52

Which series of reactions described below, if any, will result in the formation of 2-methylpentan-3-one starting with 1-propanol?

A) 1. (CH₃)₂CHMgBr/ diethyl ether
2. dilute H₃O⁺
3. PCC
B) 1. Na₂Cr₂O₇/H₂SO⁴ and heat
2. SOCl₂
3. 2 (CH₃)₂CHMgBr/ diethyl ether
4) H₃O⁺
C) 1. Na₂Cr₂O₇/H₂SO⁴ and heat
2. (CH₃)₂CHMgBr/ diethyl ether
3. dilute H₃O⁺
4. LiAlH₄
D) 1. PCC
2. (CH₃)₂CHLi/ diethyl ether
3. dilute H₃O⁺
4. Na₂Cr₂O₇/H₂SO⁴ and heat
E) none of the above

Question 53

Oxidation of a 1° alcohol with chromic acid results in the production of ________.

A) an ester
B) a ketone
C) an aldehyde
D) an ether
E) none of the above

Question 54

Oxidation of a 3° alcohol with chromic acid results in the production of ________.

A) an ester
B) a ketone
C) an aldehyde
D) an ether
E) none of the above

Question 55

Complete the following reaction by filling in the necessary reagents.

Question 56

Oxidation of a 2° alcohol with chromic acid results in the production of ________.

A) an ester
B) a ketone
C) an aldehyde
D) an ether
E) none of the above

Question 57

How might one prepare 4-heptanone from CH₃CH₂CH₂CN in two steps?

Question 58

Name the compound generated when 1-methylcyclohexene is subjected to O₃ followed by dimethyl sulfide.

Question 59

Provide the major organic product of the reaction shown below.

Question 60

Treatment of a nitrile with a Grignard reagent followed by hydrolysis results in ________.

A) an ester
B) a ketone
C) an aldehyde
D) an ether
E) an alcohol

Question 61

Propose a synthesis of 4-phenylbutan-2-ol from 3-phenylpropanal.

Question 62

An ylide is a molecule that can be described as a:

A) carbanion bound to a negatively charged heteroatom.
B) carbocation bound to a positively charged heteroatom.
C) carbocation bound to a carbon radical.
D) carbocation bound to a diazonium ion.
E) carbanion bound to a positively charged heteroatom.

Question 63

Why are the equilibrium constants for hydration of aldehydes typically greater than those of ketones?

Question 64

Provide the major organic product of the reaction shown below.

Question 65

The following compound has been found effective in treating pain and inflammation (J. Med. Chem. $\textbf{ 2007, }$ 4222). Which sequence correctly ranks each carbonyl group in order of increasing reactivity toward nucleophilic addition?

A) 1 < 2 < 3
B) 2 < 3 < 1
C) 3 < 1 < 2
D) 1 < 3 < 2

Question 66

Provide a detailed, stepwise mechanism for the base-catalyzed hydration of 2-butanone.

Question 67

Draw two major resonance forms of the cation which results when cyclohexanone's carbonyl group is protonated.

Question 68

Provide the major organic product of the reaction shown below.

Question 69

What organic compound is generated when PhCOCl is treated with (CH₃CH₂CH₂)₂CuLi?

Question 70

Rank the following compounds in order of their propensity to become a hydrate in water (i.e., start with the least easy to hydrate: CH₃COCH₂CH₃, H₂CO, Cl₃CCHO, and CH₃CH₂CHO.

Question 71

What reagent can be used to convert benzophenone into triphenylmethanol?

Question 72

When the carbonyl group of a neutral ketone is protonated,:

A) the resulting species becomes more electrophilic.
B) the resulting species is activated toward nucleophilic attack.
C) subsequent nucleophilic attack on the resulting species is said to occur under acid-catalyzed conditions.
D) the resulting species has a positive charge.
E) all of the above

Question 73

Provide the major organic product which results when (CH₃)₂CHCH₂CH₂COCl is treated with LiAlH[OC(CH₃)₃]₃.

Question 74

Provide the single reagent necessary for the conversion of cyclobutanone to the compound shown below.

Question 75

Provide the major organic product of the reaction shown below.

Question 76

Consider the equilibrium of each of the carbonyl compounds with HCN to produce cyanohydrins. Which is the correct ranking of compounds in order of increasing K_eq for this equilibrium?

A) H₂CO < cyclohexanone < CH₃CHO < 2-methylcyclohexanone
B) CH₃CHO < 2-methylcyclohexanone < cyclohexanone < H₂CO
C) cyclohexanone < 2-methylcyclohexanone < H₂CO < CH₃CHO
D) cyclohexanone < 2-methylcyclohexanone < CH₃CHO < H₂CO
E) 2-methylcyclohexanone < cyclohexanone < CH₃CHO < H₂CO

Question 77

Provide the structure of the hydrate of cyclopentanone.

Question 78

Which sequence ranks the following carbonyl compounds in order of increasing rate of nucleophilic addition?

A) 2 < 3 < 1
B) 3 < 2 < 1
C) 2 < 1 < 3
D) 1 < 3 < 2

Question 79

Through what sequence of steps can toluene be converted into PhCH₂PPh₃⁺Br^-?

Question 80

Propose a synthesis of 3-methylhept-4-yn-3-ol from but-1-yne.