Download Compounds with Oxygen Atoms

Chapter 12 Organic Compounds
with Oxygen and Sulfur
12.1
Alcohols, Thiols, and Ethers
1
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.
2
Naming Alcohols
The names of alcohols
• in the IUPAC system replace the -e with -ol.
• with common names use the name of the alkyl group
followed by alcohol.
Formula
IUPAC
CH4
methane
CH3─OH
methanol
CH3─CH3
ethane
CH3─CH2─OH
ethanol
Common Name
methyl alcohol
ethyl alcohol
3
More Names of Alcohols
IUPAC names for longer chains number the chain from
the end nearest the -OH group.
CH3─CH2─CH2─OH
1-propanol
OH
│
CH3─CH─CH2─CH3
2-butanol
CH3
OH
│
│
CH3─CH─CH2─CH2─CH─CH3 5-methyl-2-hexanol
6
5
4
3
2
1
4
Some Typical Alcohols
OH
|
“Rubbing alcohol” CH3—CH—CH3
2-propanol (isopropyl alcohol)
Antifreeze
HO—CH2—CH2—OH
1,2-ethanediol (ethylene glycol)
OH
|
Glycerol
HO—CH2—CH—CH2—OH
1,2,3-propanetriol
5
Phenols in Medicine
Phenol
• is the IUPAC name for benzene with a hydroxyl group.
• is used in antiseptics and disinfectants.
OH
OH
OH
OH
OH
CH2CH2CH2CH2CH2CH3
Phenol
Resorcinol
4-hexylresorcinol
Carbolic Acid
8
Derivatives of Phenol
Compounds of phenol are the active ingredients in the
essential oils of nutmeg, thyme, cloves, and vanilla.
OH
OH
OCH3
CH=CHCH3
isoeugenol (nutmeg)
H
C
CH3
CH3
thymol (thyme)
OH
OH
CH3
OCH3
OCH3
CH2CH=CH2
eugenol (cloves)
H
C
O
vanillin (vanilla)
9
Common Phenols/Alcohols
Cl
Cl
OH
Cl
Cl
HO
Cl
CH2
Cl
ortho-phenylphenol (Lysol)
C
OH
C
OH
3,3',5,5',6,6'-hexachlorodiphenylmethane
(hexachlorophene)
C
C
C
C
C
C
C
C
C
C
OH
trailmarker for termites
HO
CH2CH2CH2CH2CH2CH3
n-hexylresorcinol (sucrets)
10
Common Phenols/Alcohols
C
C
C
OH
OH
Cl
H
C
C
Cl
C
sex pheromone for
male Boll Weevil
C
C
C
C
C
C
C
OH
C
C
sex pheromone for Bark Beetle
sex attractant for
lonestar tick
OH
C
C
C
C
C
aggregating pheromone
for Bark Beetle
11
C
Common Phenols
OH
OH
(CH2)7
CH
CH
(CH2)5
CH3
oil of Poison Ivy
12
Herbicides produced by Phenols
Cl
Cl
O
O
C
C
OH
2,4-dichlorophenoxy acetic acid
(2,4-D)
Cl
Cl
O
O
Cl
C
C
OH
2,4,5-trichlorophenoxy acetic acid
(2,4,5-T)
13
Learning Check
Write the structure of each of the following:
A.
3-pentanol
B.
ethyl alcohol
C.
para-methylphenol
15
Solution
Write the structure of each of the following:
A. 3-pentanol
OH
|
CH3—CH2—CH—CH2—CH3
B. ethyl alcohol
CH3—CH2—OH
OH
C. para-methylphenol
CH3
16
Thiols
Thiols
• contain sulfur
• are similar to alcohols
• contain a thiol (-SH) group
• often have strong odors
• found in cheese, onions, garlic,
and oysters
• are used to detect gas leaks
17
Thiols
 are named in the IUPAC
system by adding thiol to
the alkane name of the
longest carbon chain.
(Methyl Mercaptan)
18
18
19

Striped Skunk (Mephitis mephitis) Thiols
H
CH2SH
C
C
CH3
E-2-buten-1-thiol
38-44%
3-methyl-1-butanethiol
18-26%
H
CH3
CH3CHCH2CH2SH
2-quinolinemethanethiol
N
3-12%
CH2SH
20
 For
pets that have been sprayed, bathe
the animal in a mixture of 1 quart of 3%
hydrogen peroxide (from drug store),
1/4 cup of baking soda (sodium
bicarbonate) and a teaspoon of liquid
detergent. After 5 minutes rinse the
animal with water. Repeat if necessary.
The mixture must be used after mixing
and will not work if it is stored for any
length of time. DO NOT STORE IN A
CLOSED CONTAINER - it releases
oxygen gas so it could break the
container. This mixture may bleach the
pet's hair.
21
 Why
tomato juice is believed to eliminate
skunk odor. Bathing an animal in tomato
juice seems to work because at high
doses of skunk spray the human nose
quits smelling the odor (olfactory fatigue).
When this happens, the odor of tomato
juice can easily be detected. A person
suffering olfactory fatigue to skunk spray
will swear that the skunk odor is gone
and was neutralized by the tomato juice.
Another person coming on the scene at
this point will readily confirm that the
skunk spray has not been neutralized by
the tomato juice.
22
Quickly And Safely Eliminates Odors On Pets
Thiotrol Spray is specially formulated to
neutralize, not mask, offensive skunk odor on
pets, people, clothing, carpets, and other
contaminated surfaces.
Directions
Completely saturate affected areas with the high
output pump sprayer. Work into fur, clothing, or
carpet and allow to dry. Resaturate affected area
and let dry. To avoid eyes, apply to face using a
saturated cloth. Should any odors remain, locate
odor source and reapply.
Thiotrol Spray Caution
For topical use only. Avoid contact with eyes.
Sold Exclusively Through Veterinarians
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
Propyl People Ether
24
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 1960s were nonflammable.
F
F
C
F
O
F
F
C
C
F
H
Ethrane (enflurane)
Cl
Cl
Cl
F
C
C
H
F
H
O
C
H
H
Penthrane
25
Chapter 12 Organic Compounds
with Oxygen and Sulfur
12.2
Properties of Alcohols and Ethers
26
Boiling Points of Alcohols
Alcohols
• contain polar OH
groups.
• form hydrogen bonds
with other alcohol
molecules.
• have higher boiling
points than alkanes and
ethers of similar mass.
27
Boiling Points of Ethers
Ethers
• do not have a polar
group.
• have an O atom, but
there is no H attached.
• cannot form hydrogen
bonds between ether
molecules.
28
Solubility of Alcohols and Ethers in
Water
Alcohols and ethers
• 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.
Copyright © 2009 by Pearson Education, Inc.
29
Comparing Boiling Points and
Solubility
Copyright © 2009 by Pearson Education, Inc.
30
Chapter 12 Organic Compounds
with Oxygen and Sulfur
12.3
Reactions of Alcohols and Thiols
31
Combustion of Alcohols
Alcohols undergo combustion with O2 to produce CO2
and H2O.
CH3—CH2—OH + 3O2
2CO2 + 3H2O + Energy
32
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
33
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 a decrease in the number of C-O bonds.
• there is a gain of H.
36
Oxidation and Reduction
37
Oxidation of Ethanol in the Body
In the body,
• enzymes in the liver oxidize ethanol.
• the aldehyde produced impairs coordination.
• blood alcohol over 0.4% can be fatal.
O
CH3CH2OH
Ethyl alcohol
CH3CH
Acetaldehyde
O
CH3COH
CO2
Acetic acid
38
Ethanol, CH3CH2OH
Ethanol
• acts as a depressant.
• kills or disables more
people than any other drug.
• is metabolized at a rate of
12-15 mg/dL per hour by a social
drinker.
• is metabolized at a rate of 30
mg/dL per hour by an alcoholic.
39
Alcohol Contents in Common
Products
% Ethanol
50%
40%
15-25%
20%
12%
10%
3-9%
Product
Whiskey, rum, brandy
Flavoring extracts
ListerineTM, ScopeTM
Formula 44DTM
Wine, DristanTM
NyquilTM, CepacolTM
Beer, LavorisTM
41
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─CH3
CH3─S─S─CH3 + H2O
42
Chapter 12 Organic Compounds
with Oxygen and Sulfur
12.4
Aldehydes and Ketones
43
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.
44
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.
H
C
H
Methanal
(formaldehyde)
O
O
O
CH3
C
H
Ethanal
(acetaldehyde)
CH3CH2
C
H
Propanal
(propionaldehyde)
45
•In a linear expression, the
aldehyde group is often written as:
CHO
O
C
H3C
H
is equivalent to CH3CHO
•In the linear expression of a ketone,
the carbonyl group is written as:
CO
O
C
H3C
CH3
is equivalent to CH3COCH3
Naming Aldehydes
48
Aldehydes in Flavorings
Several naturally occurring aldehydes are used as
flavorings for foods and fragrances.
O
C
H
Benzaldehyde (almonds)
O
CH
CH
C
H
Cinnamaldehyde (cinnamon)
49
Naming Ketones
In naming ketones
• in the IUPAC system, 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
CH3
Propanone
(dimethyl ketone)
CH3
C
CH2CH3
2-butanone
(ethyl methyl ketone)
50
Ketones in Common Use
Nail polish remover,
solvent
Propanone,
dimethylketone, acetone
Butter flavoring
(Butanedione)
51
Aldehydes &
Ketones in Nature
52
C
C
H
O
C
C
C
C
H
O
C
OH
C
Violet (Irone)
(Eucalyptus)
O
salicylaldehyde
(meadowsweet)
O
C
Piperonal
(Heliotrope)
O
CH3(CH2)4C
O
H
O
CH3(CH2)10C
(Citrus Fruits)
H
CH3
O
O
C
C
CH3
Raspberries
53
O
C
O
H
HO
Benzaldehyde
(Oil of Almonds)
CH
Oil of Cinnamon
H
CH3O Vanillin
O
CH
C
C
H3C
CH3
H
CH3
O
Camphor (Mothballs)
54
CH3
CH3
O
C
CHCH2CH2C
CH
C
H
CH3
Citral (Lemon Grass Oil)
O
O
C
C
C
C
C
C
C
C
C
(C)n
C
n = 4 or 6
CH3
Alarm Pheromones in ants
55
C
C
C
Boll Weevil
Sex Attractant
C
O
H
H
C
O
H
Citral
(Honey Bee Recruiting Pheromone)
56
C
(C)12
C
C
O
C
Musk Ox Sex Attractant
(C)n
C
C
O
C
(C)m
m = 4, n = 10
m = 7, n = 7
m = 7, n = 9
Civet Cat Sex Attractant
57
Learning Check
Name the following compounds:
A.
O
CH3
CH2
CH2
C
CH3
2-pentanone; methyl propyl ketone
B.
O
CH3
CH3
C
CH3
CH2
C
H
3,3-dimethylbutanal
58
Learning Check
Draw the structural formulas for each:
A. 4-methylpentanal
O
CH3
CH3
CH
CH2
B. 2,3-dichloropropanal
Cl
C. 3-methyl-2-butanone
CH3
CH2
CH2
Cl
O
CH
C
CH3
O
CH
C
C
H
H
CH3
59
Chapter 12 Organic Compounds
with Oxygen and Sulfur
12.5
Properties of Aldehydes and Ketones
Hydrogen Bond
Hydrogen Bond
Acetaldehyde
Acetone
60
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.
61
Comparison of Boiling Points
62
Solubility in Water
The electronegative O atom of the carbonyl group of
aldehydes and ketones forms hydrogen bonds with water.
Hydrogen Bond
Hydrogen Bond
Acetaldehyde
Acetone
63
Tollens’ Silver Mirror 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.
Ag+ + e– → Ag(s)
64
Benedict’s Test
In 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 brick red Cu2O(s).
65
Increasing amounts of reducing sugar
green  orange  red  brown
66