1. Chapter 12 Organic Compounds with Oxygen and Sulfur
12.1
Alcohols, Ethers, and Thiols
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2. Alcohols
An alcohol contains a hydroxyl group (—OH) attached to a carbon chain.
A phenol contains a hydroxyl group (—OH) attached to a benzene ring.
water alcohol phenol
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3. Naming Alcohols The names of alcohols
in IUPAC replace the -e with -ol.
with common names use the name of the alkyl group
followed by alcohol.
Formula IUPAC Common Name
CH4 methane
CH3─OH methanol methyl alcohol
CH3─CH3 ethane
CH3─CH2─OH ethanol ethyl alcohol

4. More Names of Alcohols
IUPAC names for longer chains number the chain from the end nearest the -OH group.
CH3─CH2─CH2─OH propanol OH │
CH3─CH─CH2─CH butanol
CH OH
│ │
CH3─CH─CH2─CH2─CH─CH methyl-2-hexanol

5. Some Typical Alcohols | “rubbing alcohol” CH3—CH—CH3
2-propanol (isopropyl alcohol)
antifreeze HO—CH2—CH2—OH
1,2-ethanediol (ethylene glycol)
glycerol HO—CH2—CH—CH2—OH
1,2,3-propanetriol

6. Learning Check Name the following compounds. 1. CH3—CH2—CH2—CH2—OH
OH CH3
| |
2. CH3—CH—CH—CH2—CH3 3.

7. Solution OH CH3 | | 2. CH3—CH—CH—CH2—CH3 3-methyl-2-pentanol
1. CH3—CH2—CH2—CH2—OH 1-butanol
OH CH3
| |
2. CH3—CH—CH—CH2—CH methyl-2-pentanol
cyclopentanol

8. Phenols in Medicine Phenol
is the IUPAC name for benzene with a hydroxyl group.
is used in antiseptics and disinfectants.
phenol resorcinol hexylresorcinol

9. Derivatives of Phenol
Compounds of phenol are the active ingredients in the essential oils of cloves, vanilla, nutmeg, and mint.

10. Naming Phenols To name a phenol
with two substituents, assign C-1 to the carbon attached to the –OH.
number the ring to give the lowest numbers. 1 1 3 4
3-chlorophenol bromophenol

11. Learning Check Write the structure of each of the following.
A pentanol
B. ethyl alcohol
C methylphenol

12. Solution Write the structure of the following. A. 3-pentanol OH |
CH3—CH2—CH—CH2—CH3
B. ethyl alcohol CH3—CH2—OH
C. 4-methylphenol O H C 3

13. Classification of Alcohols
Classification of alcohols is
determined by the number of alkyl groups attached to the carbon bonded to the hydroxyl.
primary (1°), secondary (2°), or tertiary(3).
Primary (1º) Secondary (2º) Tertiary (3º) 1 group groups 3 groups H CH CH | | |
CH3—C—OH CH3—C—OH CH3—C—OH | | | H H CH3

14. Learning Check 1) primary, 2) secondary, or 3) tertiary. OH |
Classify each alcohol as
1) primary, 2) secondary, or 3) tertiary. OH |
A. CH3—CH—CH2—CH3
B. CH3—CH2—CH2—OH
C. CH3—CH2—C—CH2—CH3
CH3

15. Solution | A. CH3—CH—CH2—CH3 secondary B. CH3—CH2—CH2—OH primary
C. CH3—CH2—C—CH2—CH3 tertiary
CH3

16. Thiols Thiols are carbon compounds that contain a –SH group.
are named in the IUPAC system by adding thiol to the alkane name of the longest carbon chain.
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17. Thiols Thiols often have strong odors. are used to detect gas leaks.
are found in onions, oysters, and garlic.

18. Ethers An ether contains an ─O─ between two carbon groups.
has a common name that gives the alkyl names of the attached groups followed by ether.
CH3─O─CH3 CH3─CH2─O─CH3
dimethyl ether ethyl methyl ether

19. Learning Check Write the structure of the following. A. 3-pentanol
B. diethyl ether

20. Solution OH | A. 3-pentanol CH3─CH2─CH─CH2─CH3
B. diethyl ether CH3─CH2─O─CH2─CH3

21. Ethers as Anesthetics Anesthetics inhibit pain signals to the brain.
like diethyl ether CH3─CH2─O─CH2─CH3 were used for over a century, but caused nausea and were flammable.
developed by the 1960’s were nonflammable.
Cl F F Cl F H
│ │ │ │ │ │
H─C─C─O─C─H H─C─C─O─C─H
F F F H F H
Ethane(enflurane) Penthrane

22. MTBE Methyl tert-butyl ether CH3 │ CH3─O─C─CH3
is second in production of organic chemicals.
is an additive used to improve gasoline performance.
use is questioned since the discovery that MTBE has contaminated water supplies.

23. Chapter 12 Organic Compounds with Oxygen and Sulfur
12.2
Properties of Alcohols, Ethers,
and Thiols
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24. Boiling Points of Alcohols
contain polar OH groups.
form hydrogen bonds with other alcohol molecules.
have higher boiling points than alkanes and ethers of similar mass.
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25. Boiling Points of Ethers
do not have a polar group.
have an O atom, but there is no H attached.
cannot form hydrogen bonds between ether molecules.
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26. Solubility of Alcohols and Ethers in Water
are more soluble in water than alkanes because the oxygen atom can hydrogen bond with water.
with 1-4 C atoms are soluble, but not with 5 or more C atoms.

27. Comparing Solubility and Boiling Points
Molar Boiling Soluble
Compound Mass Point (°C) in Water?
Alkane CH3─CH2─CH No
Ether CH3─O─CH Yes
Alcohol CH3─CH2─OH Yes

28. Solubility of Phenol Phenol is soluble in water.
has a hydroxyl group that ionizes slightly (weak acid).
is corrosive and irritating to skin.
+ H2O H3O+

29. Chapter 12 Organic Compounds with Oxygen and Sulfur
12.3
Reactions of Alcohols and Thiols
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30. Combustion of Alcohols
Alcohols undergo combustion with O2 to produce CO2 and H2O.
2CH3OH + 3O CO H2O + Heat
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31. Dehydration of Alcohols
Alcohols undergo
dehydration when heated with an acid catalyst.
the loss of —H and —OH from adjacent carbon atoms.
H OH
| | H+, heat
H—C—C—H H—C=C—H + H2O
| | | |
H H H H
alcohol alkene

32. Learning Check
Write the equations for the reaction of 2-propanol when it
undergoes
1. combustion.
2. dehydration.

33. Solution OH │ CH3─CH─CH3 = 2-propanol = C3H8O 1. combustion
2C3H8O + 9O CO H2O
2. dehydration
│ H+
CH3─CH─CH CH3─CH=CH2 + H2O

34. Oxidation and Reduction
In an oxidation,
there is an increase in the number of C-O bonds.
there is a loss of H.
In a reduction,
there is an decrease in the number of C-O bonds.
there is a gain of H.

35. Oxidation and Reduction

36. Oxidation of Primary (1) Alcohols
When a primary alcohol is oxidized, [O],
one H is removed from the –OH.
another H is removed from the carbon bonded to the OH.
an aldehyde is produced.
[O]
Primary alcohol Aldehyde
OH O
| [O] ||
CH3—C—H CH3—C—H + H2O | H
Ethanol Ethanal
(ethyl alcohol) (acetaldehyde)

37. Oxidation of Secondary (2) Alcohols
When a secondary alcohol is oxidized, [O],
one H is removed from the –OH.
another H is removed from the carbon bonded to the OH.
a ketone is produced.
[O]
secondary alcohol ketone
OH O
│ [O] ║
CH3─C─CH CH3─C─CH3 + H2O │ H
2-propanol (isopropyl alcohol) propanol (dimethyl ketone)

38. Oxidation of Tertiary ( 3)Alcohols
Tertiary 3alcohols do not readily oxidize [O]
Tertiary alcohol no reaction OH
│ [O]
CH3─C─CH3 no product │
CH no H on the C-OH to oxidize
2-methyl-2-propanol

39. Oxidation of Ethanol in the Body
enzymes in the liver oxidize ethanol.
aldehyde product impairs coordination.
blood alcohol over 0.4% can be fatal O O
║ ║
CH3CH2OH CH3CH CH3COH CO2 + H2O
ethyl alcohol acetaldehyde acetic acid

40. Ethanol CH3CH2OH Ethanol acts as a depressant.
kills or disables more people than any other drug.
is metabolized at a rate of mg/dL per hour by a social drinker.
is metabolized at a rate of 30 mg/dL per hour by an alcoholic.

41. Effect of Alcohol on the Body

42. Alcohol Contents in Common Products
% Ethanol Product
50% Whiskey, rum, brandy
40% Flavoring extracts
15-25% Listerine, Nyquil, Scope
12% Wine, Dristan, Cepacol
3-9% Beer, Lavoris

43. Oxidation of Thiols When thiols undergo oxidation,
an H atom is lost from each of two –SH groups.
the product is a disulfide.
[O]
CH3─SH + HS─CH CH3─S─S─CH3 + H2O

44. Learning Check OH │ [O] CH3─CH─CH2─CH3 O ║
Select the product for the oxidation of OH
│ [O]
CH3─CH─CH2─CH3
O ║
1) CH3─CH=CH─CH ) CH3─C─CH2 ─CH3 │
3) CO2 + H2O ) CH3─CH─CH2─CH3

45. Solution OH │ [O] CH3─CH─CH2─CH3 O ║ 2) CH3─C─CH2 ─CH3
Select the product for the oxidation of OH
│ [O]
CH3─CH─CH2─CH3
O ║
2) CH3─C─CH2 ─CH3

46. Learning Check A) H+, heat B) [O] C) + O2 1) CH3—CH=CH2 2) CO2 + H2O O
Select the product when CH3—CH2—CH2—OH undergoes each of the following reactions:
A) H+, heat B) [O] C) + O2
1) CH3—CH=CH2
2) CO2 + H2O O ||
3) CH3—CH2—C—H

47. Solution O [O] || B. 3) CH3—CH2—C—H C. + O2 2) CO2 + H2O
A. H+, heat 1) CH3—CH=CH2 O
[O] ||
B ) CH3—CH2—C—H
C. + O2 2) CO2 + H2O

48. Chapter 12 Organic Compounds with Oxygen and Sulfur
12.4
Aldehydes and Ketones

49. Carbonyl Group in Aldehydes and Ketones
A carbonyl group
in an aldehyde is attached to at least one H atom.
in a ketone is attached to two carbon groups.

50. Naming Aldehydes An aldehyde
has an IUPAC name in which the -e in the alkane name is changed to –al.
has a common name for the first four aldehydes that use the prefixes: form (1C), acet (2C), propion (3C), and butyr (4C), followed by aldehyde.
O O O
║ ║ ║
H─C─H CH3─C─H CH3─CH2─C─H
methanal ethanal propanal
(formaldehyde) (acetaldehyde) (propionaldehyde)

51. Naming Aldehydes

52. Aldehydes in Flavorings
Several naturally occurring aldehydes are used as flavorings for foods and fragrances.
Benzaldehyde (almonds)
Cinnamaldehyde (cinnamon)

53. Naming Ketones In naming ketones
as IUPAC, the -e in the alkane name is replaced with
–one.
With a common name, the alkyl groups attached to the carbonyl group are named alphabetically followed
by ketone.
O O
║ ║
CH3 ─C─CH CH3─C─CH2─CH3 propanone butanone
(dimethyl ketone) (ethyl methyl ketone)

54. Ketones in Common Use Nail polish remover, solvent
Propanone, Dimethylketone, Acetone
Butter flavoring

55. Learning Check Classify each as 1) aldehyde or 2) ketone. O O || ||
|| ||
A. CH3—CH2—C—CH B. CH3—C—H
CH O
| ||
C. CH3—C—CH2—C—H D. |
CH3

56. Solution
A. 2 ketone
B. 1 aldehyde
C. 1 aldehyde
D. 2 ketone

57. Learning Check Classify each as an
1) aldehyde 2) ketone 3) alcohol or 4) ether. O ║
A. CH3─CH2─C─CH3 B. CH3─O─CH3
CH O OH
│ ║ │
C. CH3─C─CH2─C─H D. CH3─CH ─CH3 │
CH3

58. Solution O ║ A. CH3─CH2─C─CH3 B. CH3─O─CH3 2) ketone 4) ether CH3 O OH
│ ║ │
C. CH3─C─CH2─C─H D. CH3─CH─CH3 │
CH3
1) aldehyde ) alcohol

59. Learning Check Name each of the following. O ║ 1. CH3─CH2─CH2─CH2─C─H
2. Cl─CH2─CH2─C─H
3. CH3─CH2─C─CH3

60. Solution Name each of the following: O ║
1. CH3─CH2─CH2─CH2─C─H pentanal
2. Cl─CH2─CH2─C─H 3-chloropropanal
3. CH3─CH2─C─CH3 2-butanone;
ethyl methyl ketone

61. Learning Check Name the following compounds. O ||
A. CH3—CH2—CH2—C—CH B.
CH O
| ||
C. CH3—C—CH2—C—H |
CH3

62. Solution A. 2-pentanone; methyl propyl ketone B. cyclohexanone
C, 3,3-dimethylbutanal

63. Learning Check Draw the structural formulas for each:
A. 4-methylpentanal
B. 2,3-dichloropropanal
C. 3-methyl-2-butanone

64. Solution Draw the structural formulas for each: CH3 O │ ║
A. 4-methylpentanal CH3─CH─CH2─CH2─C─H
Cl O
│ ║
B. 2,3-dichloropropanal Cl─CH2─CH─C─H
CH3 O
C. 3-methyl-2-butanone CH3─CH─C─CH3

65. Chapter 12 Organic Compounds with oxygen and Sulfur
12.5
Properties of Aldehydes and Ketones

66. Physical Properties
The polar carbonyl group provides dipole-dipole interactions.
+  + -
C=O C=O
Without an H on the oxygen, aldehydes and ketones cannot form hydrogen bonds.

67. Boiling Points + - + - + - Aldehydes and ketones have
polar carbonyl groups (C=O).
+ -
C=O
attractions between polar groups.
+  + -
C=O C=O
higher boiling points than alkanes and ethers of similar mass.
lower boiling points than alcohols of similar mass.

68. Comparison of Boiling Points58

69. Solubility in Water
The electronegative O atom of the carbonyl group of aldehydes and ketones forms hydrogen bonds with water.

70. Learning Check Indicate if each is soluble or insoluble in water.
A. CH3—CH2—CH3
B. CH3—CH2—OH O ||
C. CH3—CH2—CH2—C—H
D. CH3—C—CH3

71. Solution Indicate if each is soluble or insoluble in water.
A. CH3—CH2—CH3 insoluble
B. CH3—CH2—OH soluble O ||
C. CH3—CH2—CH2—C—H soluble
D. CH3—C—CH soluble

72. Tollens’ Test In Tollens’ test, Tollens’ reagent,
which contains Ag+, oxidizes aldehydes, but not ketones.
Ag+ is reduced to metallic Ag, which appears as a “mirror” in the test tube.

73. Benedict’s Test In the Benedict’s test,
Benedict’s reagent, which contains Cu2+, reacts with aldehydes that have an adjacent OH group.
An aldehyde is oxidized to a carboxylic acid, while Cu2+ is reduced to give red Cu2O(s).

74. Learning Check Write the structure and name of the oxidized product
when each is mixed with Tollens’ reagent.
A. butanal
B. acetaldehyde
C. ethyl methyl ketone

75. Solution A. butanal O || CH3—CH2—CH2—C—OH butanoic acid
B. acetaldehyde O
CH3—C—OH
acetic acid
C. ethyl methyl ketone None.
Ketones are not oxidized by Tollen’s reagent.

76. Chapter 12 Organic Compounds with Oxygen and Sulfur
12.6
Chiral Molecules
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77. Chiral Objects Chiral objects
have the same number of atoms arranged differently in space.
have one or more chiral carbon atoms each of which is bonded to four different groups.
are like your hands. Try to superimpose your thumbs, palms, back of hands, and little fingers.
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78. Mirror Images
The mirror images of chiral compounds cannot be superimposed.
When the H and I atoms are aligned, the Cl and Br atoms are on opposite sides.

79. Achiral Structures are Superimposable
When the mirror image of an achiral structure is rotated, the structure can be aligned with the initial structure. Thus this mirror image is superimposable.

80. Some Everyday Chiral and Achiral Objects

81. Learning Check
Identify each as a chiral or achiral compound. A C H 2 3 l B r

82. Solution chiral achiral chiral A C H l B r
Identify each as a chiral or achiral compound.
chiral achiral chiral A C H 2 3 l B r

83. Fischer Projections A Fischer projection
is a 2-dimensional representation of a 3-dimensional molecule.
places the most oxidized group at the top.
uses vertical lines in place of dashes for bonds that go back.
uses horizontal lines in place of wedges for bonds that come forward.

84. Drawing Fischer Projections

85. D and L Notations
By convention, the letter L is assigned to the structure with the —OH on the left.
The letter D is assigned to the structure with the —OH on the right.
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86. Learning Check
Indicate whether each pair is a mirror image that cannot be superimposed (enantiomers).

87. Solution
Indicate whether each pair is a mirror image that cannot be superimposed (enantiomers).
Yes No