Download Chapter 1.4 Alcohols, Ethers and Thiols

CHAPTER 1.4
Alcohols, Ethers and Thiols
Learning Objective:
Learn the nomenclature and uses of Alcohols,
Ethers and Thiols.
Keywords:
Alcohol, Primary Alcohol, Secondary Alcohol, Tertiary
Alcohol, Phenol, Thiols, Ether
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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
Copyright © 2005 by
Pearson Education, Inc.
Publishing as Benjamin
Cummings
2
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
CH4
methane
CH3─OH
methanol
CH3─CH3
ethane
CH3─CH2─OH
ethanol
Common Name
methyl alcohol
ethyl alcohol
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Names the following Alcohols
IUPAC names for longer chains - number the chain from
the end nearest the -OH group.
CH3─CH2─CH2─OH
OH
│
CH3─CH─CH2─CH3
CH3
OH
│
│
CH3─CH─CH2─CH2─CH─CH3
6
5
4
3
2
1
4
More Names of Alcohols - Answers
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
6
5
4
3
2
1
5-methyl-2-hexanol
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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
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Task
Name the following compounds.
1. CH3—CH2—CH2—CH2—OH
2.
2 minutes
OH CH3
|
|
CH3—CH—CH—CH2—CH3
OH
End
3.
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Solution
1. CH3—CH2—CH2—CH2—OH
OH CH3
|
|
2. CH3—CH—CH—CH2—CH3
1-butanol
3-methyl-2-pentanol
OH
3.
cyclopentanol
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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 or benzenediol
4-hexylresorcinol
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Derivatives of Phenol
Compounds of phenol are the active ingredients in the
essential oils of cloves, vanilla, nutmeg, and mint.
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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.
OH
1
OH
1
3
Cl
3-chlorophenol
4
Br
4-bromophenol
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Task
Write the structure of each of the following.
A.
3-pentanol
B.
ethyl alcohol
C.
4-methylphenol
2 minutes
End
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Solution
Write the structure of the following.
A. 3-pentanol
OH
|
CH3—CH2—CH—CH2—CH3
B. ethyl alcohol
CH3—CH2—OH
OH
C. 4-methylphenol
CH3
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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)
1 group
H
|
CH3—C—OH
|
H
Secondary (2º)
Tertiary (3º)
2 groups
3 groups
CH3
|
CH3—C—OH
|
H
CH3
|
CH3—C—OH
|
CH3
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Task
Classify each alcohol as
1) primary, 2) secondary, or 3) tertiary.
OH
|
A. CH3—CH—CH2—CH3
2 minutes
B. CH3—CH2—CH2—OH
OH
|
C. CH3—CH2—C—CH2—CH3
|
CH3
End
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Solution
OH
|
A. CH3—CH—CH2—CH3
secondary
B. CH3—CH2—CH2—OH
primary
OH
|
C. CH3—CH2—C—CH2—CH3
|
CH3
tertiary
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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.
Copyright © 2005 by Pearson Education, Inc.
Publishing as Benjamin Cummings
17
Thiols
Thiols
• often have
strong smells.
• are used to
detect gas leaks.
• are found in
onions, oysters,
and garlic.
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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
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Task
Write the structure of the following.
A. pentyl propyl ether
2 minutes
B. diethyl ether
End
20
Solution
A. pentyl propyl ether
B. diethyl ether
CH3─CH2─O─CH2─CH3
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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
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TASK
Answer the questions on the handout. If you don’t finish it
in class, do it for homework please 
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