Download Alcohols, Phenols, and Ethers

Alcohols, Phenols, and Ethers
Dr. Sean Bonness
Chemistry Department
El Camino College
Introduction to alcohols
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Some examples of alcohols
Hydroxy (-OH) is the functional group.
Alcohol has an -OH group attached to an aliphatic
carbon. General formula is R-OH.
Phenol has an -OH group on a benzene ring.
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Nomenclature of alcohols and
phenols

IUPAC rules
 Step 1: Name the longest chain to which the
hydroxy group is attached. Drop the final -e from
the hydrocarbon and add the ending -ol.
Nomenclature of alcohols and
phenols

IUPAC rules (cont.)
 Step 2: Number the longest chain to give the lower
number to carbon with attached hydroxy group.
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Step 3: Find the position of hydroxy group by the
number of the carbon atom attached to it.
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Nomenclature of alcohols and
phenols

IUPAC rules (cont.)
 Step 4: Find and name any branches.
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Step 5: Combine the name and location of other
groups, hydroxy group location, and long chain
into final name.
Nomenclature of alcohols and
phenols

Name the following alcohols according to IUPAC
system:
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Nomenclature of alcohols and
phenols
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Alcohols containing two hydroxy groups are called
diols. Those containing three are called triols.
IUPAC rules are the same as single hydroxy alcohols,
except the ending is -diol, or -triol goes on end of
parent hydrocarbon.
Nomenclature of alcohols and
phenols

Assign IUPAC names to the following alcohols
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Nomenclature of alcohols and
phenols
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Naming phenols
 Substituted phenols are usually named as
derivatives of the parent compound phenol.
Classification of alcohols

We have seen classification of carbons on alkanes
before, such as primary, secondary, and tertiary
carbons. The same classification goes for the carbon
that has the hydroxy group.
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Primary alcohols
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Secondary alcohols
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Tertiary alcohols
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Classification of alcohols
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Classify the following alcohols as primary,
secondary, or tertiary
The –OH group is polar and capable of
hydrogen bonding.
This makes low molecular weight alcohols
highly soluble in water.
Hydrogen bonding in a water-methanol
solution:
Physical properties of alcohols
Lower molecular weight
alcohols are soluble in water.
 This is due to hydrogen
bonding between hydroxy group
and water.

As molecular weight increases for
alcohols, they become more
“alkanelike”. Long chain alcohols
are less soluble in water and more
soluble in nonpolar solvents, like
benzene.
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Physical properties of alcohols
Physical properties of alcohols

Which member of each of the following pairs aould
be more soluble in water? Why?

Butane or 2-butanol
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2-propanol or 2-pentanol

2-butanol or 2,3-butanediol
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Reactions of alcohols
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Dehydration to produce an alkene
The removal of water (dehydration) from an alcohol
at 180°C is an elimination reaction that produces an
alkene.
Reactions of alcohols

Dehydration to produce an alkene
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Reactions of alcohols

Dehydration to produce an alkene
Reactions of alcohols

Dehydration to produce an ether
Under slightly different conditions (140°C), a
dehydration reaction can occur between two
alcohol molecules to produce an ether.
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Reactions of alcohols

Dehydration to produce an ether
Reactions of alcohols

Oxidation – the removal of hydrogen atoms
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Reactions of alcohols

Three classes of alcohols react differently to oxidizing
agents.
 Primary alcohols
Reactions of alcohols

Three classes of alcohols react differently to oxidizing
agents.
 Secondary alcohols
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Reactions of alcohols

Three classes of alcohols react differently to oxidizing
agents.
 Tertiary alcohols
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