2. Introduction
• Alcohol – organic compound that contains
a hydroxyl (-OH) group attached to an
alkyl group
• Phenol – organic compound that contains
a hydroxyl (-OH) group attached to an aryl
group
• Ether – organic compound that has two
alkyl or aryl groups attached to the oxygen
atom; can be thought of as a substituted
alcohol.
4. Practice Problem 1
Classify each as an alcohol (1), phenol (2), or
an ether (3):
A. _____ CH3CH2-O-CH3 C. _____ CH3CH2OH
B. _____
OH
CH3
5. Solution 1
Classify each as an alcohol (1), phenol (2), or
an ether (3):
A. ____ CH3CH2-O-CH3 C. ____ CH3CH2OH
B. _ __
OH
CH3
6. Structure and Properties
• R-O-H portion of alcohol is similar to the
structure of water.
– The oxygen and two atoms bonded to it lie in
the same plane.
– The bond angle is 104°
• Hydroxyl groups are very polar because of
significantly different electronegativities.
– Hydrogen bonding can form between alcohol
molecules.
8. Results of Hydrogen Bonding
• Alcohols boil at much higher temperatures
than hydrocarbons of similar molecular
weight.
• Alcohols with fewer than five carbons are
very soluble in water.
• Alcohols with five to eight carbons are
moderately soluble in water.
• As the nonpolar (R) portion of the alcohol
gets larger, the water solubility decreases.
9. • Very large alcohols are not soluble in
water.
• Hydrophobic – “water fearing”; used to
describe nonpolar region of molecule
• Hydrophilic – “water loving”; used to
describe polar region of molecule
CH3CH2CH2CH2CH2CH2CH2CH2CH2OH
Hydrophobic Hydrophilic
Solubility of Alcohols
10. Solubility of Alcohols
• An increase in the number of hydroxyl
groups will increase the influence of the
polar hydroxyl group.
–Diols and triols are more water soluble
than alcohols with only a single hydroxyl
group.
11. Practice Problem 2
• Circle the more soluble alcohol in each pair.
H3C C
H2
OH
A. OR
H3C
H2
C
C
H2
H2
C
OH
B.
OH
OH
OR OH
C. OR
OH
12. Solution 2
• Circle the more soluble alcohol in each pair.
H3C C
H2
OH
A. OR
H3C
H2
C
C
H2
H2
C
OH
B.
OH
OH
OR OH
C. OR
OH
13. Nomenclature of Alcohols
• A carbon compound that contain -OH
(hydroxyl) group
• In IUPAC name, the -e in alkane name is
replaced with -ol.
CH4 methane
CH3OH methanol (methyl alcohol)
CH3CH3 ethane
CH3CH2OH ethanol (ethyl alcohol)
14. More Names of Alcohols
• IUPAC names for longer chains number the
chain from the end nearest the -OH group.
CH3CH2CH2OH
OH
CH3CHCH3
CH3 OH
CH3CHCH2CH2CHCH3
15. Alcohols that contain more than
one hydroxyl group
• Alcohols containing two hydroxyl groups
are named –diols.
• Alcohols containing three hydroxyl groups
are named –triols.
• A number giving the position of each of the
hydroxyl groups is needed in these cases.
19. Section 13.3
• It is your responsibility to read
over section 13.3 – Medically
Important Alcohols (pgs. 360-
361) and take notes on the
material covered!
• It will be on the weekly quiz
and the test!
20. Classification of Alcohols
• Alcohols can be classified as primary (1°),
secondary (2°), or tertiary (3°) depending on the
number of alkyl groups attached to the carbon
bearing the –OH group.
C
H
H
H
OH
H3C C
H
OH
H
H3C C
CH3
OH
H H3C C
CH3
CH3
OH
Methanol 1° alcohol 2° alcohol 3° alcohol
ethanol 2-propanol 2-methyl-2-propanol
21. Practice Problem 4
Classify each of the following alcohols
as primary, secondary, tertiary, or
aromatic.
1. 1-butanol
2. 3-pentanol
3. 1-methylcyclopentanol
4. 2-methyl-2-pentanol
23. Homework
• Pages 380-381: 13.15,
13.16, 13.18, 13.19, 13.20,
13.21, 13.22, 13.27, and
13.28
Due Tomorrow!
24. Preparation of Alcohols
• REVIEW: Hydration – an addition reaction in
which a water molecule is added to an alkene;
requires acid as catalyst
R
R
R R
+
H
O H
H+
H
R
R
R OH
R
Alkene Water Alcohol
Markovnikov’s rule applies!!
26. Preparation of Alcohols
• Hydrogenation of aldehydes and ketones
O
R1 R2
+
H
H
H
R2
R1
OH
Catalyst
In an aldehyde, R1 and R2 may be either alkyl groups or H.
In a ketone, R1 and R2 are both alkyl groups.
We will discuss this in more detail in section 14.4.
29. Dehydration of Alcohols
• Alcohols undergo dehydration (lose water)
when heating with concentrated sulfuric or
phosphoric acid.
• Dehydration is an example of an
elimination reaction.
• Elimination reaction – a reaction in which a
molecule loses atoms or ions from its
structure.
• Dehydration is opposite of hydration!
30. Dehydration of Alcohols
• General Reaction
• Ethanol
• 2-butanol
RCH2CH2OH
H+
RCH=CH2 + H2O
CH3CH2OH
H+
C C C C
H
H
H H
H H
OH
H
H
H
H+
Heat
Heat
Heat
31. Dehydration of Alcohols
• Zaitsev’s rule – in an elimination reaction,
the alkene with the greatest number of
alkyl groups on the double bonded carbon
(more highly substituted alkene) is the
major product of the reaction
• Another example:
32. Oxidation Reactions
• Oxidation – loss of electrons; add O and/or
lose H
• Reduction – gain of electrons; add H
and/or lose O
• Common oxidizing agents:
– Basic potassium permanganate (KMnO4/OH-)
– Chromic Acid (H2CrO4)
• [O] Any general oxidizing agent
33. Oxidation of Primary Alcohols
• General equation:
– Primary alcohol aldehyde
RCH2CH=O
EXAMPLE:
1-propanol
35. Oxidation of Tertiary Alcohols
• General equation:
– Tertiary alcohol NO REACTION!!!
36. YOU TRY THESE!
C C C C
H
H
H H
H H
OH
H
H
H
[O]
OH
[O]
O
H
[O]
CH3CH2OH
[O]
37. Phenols
• Phenols – compounds in which the
hydroxyl group is attached to a benzene
ring
• They are polar compounds because of the
polar hydroxyl group.
• Smaller phenols are somewhat soluble in
water.
• They are found in fragrances and
flavorings and are also used as
preservatives and germicides.
38. Common Phenols and their
Uses
CH3
OH
(CH3)2HC Thymol (mint)
CH3
OH
(CH3)2HC
Carvacrol (savory)
39. Common Phenols and their
Uses
OH
(CH3)3C
CH3
C(CH3)3
Butylated hydroxytoluene,
BHT(Food preservative)
OH
Phenol
(Carbolic acid when dissolved in water)
Antiseptic and disinfectant used by
Joseph Lister to bathe wounds and sterlize
instruments
41. Ethers
• What are they?
• How are they used?
• What do you know about them?
42. Structure of Ethers
• Similar structure to alcohols
Alcohols: R-OH
–OH is “hydroxy” group
Ethers: R-OR
–OR is “alkoxy” group
43. Alkoxy group
• “R” groups can be
the same:
CH3-O-CH3
• Both “R” groups
have one carbon
• “R” groups can be
different:
CH3CH2CH2-O-CH3
• One “R” group has
three carbons while
the other has one
44. Alkoxy group
• The root names are used with –oxy to
name that portion of the ether:
– meth- + -oxy
– eth- + -oxy
– prop- + -oxy
= methoxy
= ethoxy
= propoxy
45. Naming ethers – IUPAC Way
1. Find the root name of the smaller “R” group
Ex: meth-, eth-, prop-
2. Add –oxy
Ex: methoxy, ethoxy, propoxy
3. Add the full name of the larger “R” group
EXAMPLE:
O
methoxypropane
49. Naming Ethers – Common
Name
• Name by placing the names of the two alkyl
groups attached to the ether oxygen as words
in front of the word “ether.” Typically this is
done in alphabetical order.
O O
O
Diethyl Ether Ethyl methyl ether
Butyl propyl ether
50. Properties of ethers
• The C-O bond in ethers is polar, making
the molecule polar
• Ethers have very low boiling points
• Ethers are relatively inert, but flammable
in air
52. Preparing ethers
• Ethers are formed from alcohols
R-OH + R’-OH R-O-R’ +H2O
–R and R’ can be the same or
different
–Called a dehydration reaction
H+
55. Common uses
• Ethers as anesthetics:
– Penthrane
– Enthrane
• Ethers as additives in gasoline
– MTBE – methyl tert-butyl ether
56. Thiols
• Compounds that contain the sulfhydryl
group (-SH)
• Similar to alcohols in structure, but the
sulfur atom replaces the oxygen atom
• Have nauseating aromas – defense spray
of North American striped skunk
H2C
CH3
H
H
SH
Trans-2-butene-1-thiol
57. Naming Thiols
• Use the same rules as for alcohols except
that the full name of the alkane is retained.
• Add the suffix –thiol.
CH3CH2SH
CH3CHCH2CH2
CH3
SH
HSCH2CH2SH
ethanethiol
3-methyl-1-butanethiol
1,2-ethanedithiol
58. Uses of Thiols
• Thiols are involved in protein structure and
conformation.
• Cysteine is an amino acid that contains a
sulfhydryl group.
• BAL (British Anti-Lewisite) is used as an
antidote for mercury poisoning.
• Coenzyme A serves as a carrier of acetyl
groups in biochemical reactions.
