Transcript Alcohols

Compounds with Oxygen Atoms
Alcohols
-OH hydroxyl
CH3-OH
CH3CH2-OH
OH
OH
Phenols
Ethers
-O-
CH3-O-CH3
Learning Check
Classify each as an alcohol (1), phenol (2), or an ether
(3):
A. _____ CH3CH2-O-CH3 C. _____ CH3CH2OH
OH
B. _____
CH3
Solution
Classify each as an alcohol (1), phenol (2), or an ether
(3):
A. __3__ CH3CH2-O-CH3 C. __1__ CH3CH2OH
B. _ 2__
OH
CH3
Naming 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)
Alcohols
 How
is the -OH group different
from the hydroxide ion?
-OH group forms covalent bond with the carbon
Hydroxide ion forms ionic bond with a metal
Ethanol CH3CH2OH
 Acts as a depressant
 Kills or disables more people than any
other drug
 12-15 mg/dL ethanol metabolized by a
social drinkers in one hour
 30 mg/dL ethanol metabolized by an
alcoholic in one hour.
Alcohol in Some Products
% Ethanol
Product
50%
40%
15-25%
12%
3-9%
Whiskey, rum, brandy
Flavoring extracts
Listerine, Nyquil, Scope
Wine, Dristan, Cepacol
Beer, Lavoris
More Names of Alcohols

IUPAC names for longer chains number the chain
from the end nearest the -OH group.
CH3CH2CH2OH
1-propanol
OH
CH3CHCH3
CH3
2-propanol
OH
CH3CHCH2CH2CHCH3
5-methyl-2-hexanol
Some Typical Alcohols
OH
“rubbing alcohol”
CH3CHCH3
2-propanol (isopropyl alcohol)
antifreeze HO-CH2-CH2-OH
1,2-ethanediol (ethylene glycol)
OH
glycerol
HO-CH2-CH-CH2OH
Classification of Alcohols
Primary (1º)
H
Secondary (2º )
CH3
CH3-C-OH
CH3-C-OH
H
H
1C
attached
to C-OH
2C
attached
to C-OH
Tertiary (3º)
CH3
CH3-C-OH
CH3
3C
attached
to C-OH
Learning Check
Classify the following as 1º, 2º, or 3º alcohols:
OH
A. CH3CH2CH2OH
C.
OH
B. CH3-CH-CH2CH3
D.
OH
CH3-C-CH2CH3
CH3
Solution
Classify the following as 1º, 2º, or 3º alcohols:
OH
A. CH3CH2CH2OH 1º
C.
OH
2º
B. CH3-CH-CH2CH3 2º
D.
OH
3º
CH3-C-CH2CH3
CH3
Properties of Alcohols
Ethyl alcohol (ethanol) used in the
intoxicating beverages; an important
industrial solvent
 Many aliphatic alcohols used in
laboratories, clinics, and industry
– Isopropyl alcohol (2-propanol) is
rubbing alcohol; used as antiseptic, and
a base for perfume, creams, lotions,
and other cosmetics

Properties of Alcohols
 Glycerol
(1,2,3-propanetriol) - used
as a moistening agent in cosmetics,
foods, and drugs; also a
component of fats and oils
Learning Check
Name the following alcohols:
A.
OH
CH3CHCHCH2CH3
CH3
OH
B.
Solution
Name the following alcohols:
A.
OH
3-methyl-2-pentanol
CH3CHCHCH2CH3
CH3
OH
B.
cyclobutanol
Properties of Alcohols
 Much
like water, alcohols are
capable of hydrogen bonding
between molecules
–this means they will boil at a
higher temp. than alkanes and
halocarbons with a comparable
number of atoms
Properties of Alcohols
 Alcohols
of up to 4 carbons are
soluble in water in all proportions;
more than 4 carbons are usually
less soluble, because…?
Properties of Alcohols
 Denatured
alcohol- means it has
been made poisonous by the
addition of other chemicals, often
methyl alcohol (methanol, or wood
alcohol). As little as 10 mL of
methanol has been known to cause
permanent blindness, and 30 ml
has resulted in death!!!
Reactions of Alcohols
Combustion
CH3OH + 2O2
Dehydration
H OH
H-C-C-H
H H
alcohol
CO2 + 2H2O + Heat
H+, heat
H-C=C-H + H2O
H H
alkene
Oxidation
Is a gain of oxygen (O)
or
A loss of hydrogen (H)
Oxidation of Alcohols
1°alcohols are oxidized to
aldehydes and 2° alcohols are
oxidized to ketones
Alcohols
1°
2°
aldehydes ketones
Oxidation of Alcohols
[O]
Primary alcohol
OH
[O]
CH3-C-H
aldehyde
O

CH3-C-H
H
Ethanol
(ethyl alcohol)
Ethanal
(acetaldehyde)
Oxidation of Alcohols
[O]
Secondary alcohol
OH
[O]
CH3-C-CH3
2-Propanol
(isopropyl alcohol)
ketone
O

CH3-C-CH3
2-propanone
(dimethyl ketone,
“acetone”)
Oxidation of Alcohols
[O]
Tertiary alcohols
OH
no reaction
[O]
CH3-C-CH3
CH3
no product
no H on the C-OH to oxidize
2-Methyl-2-propanol
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
[O]
 [O]

CH3CH2OH
CH3CH
CH3COH
2CO2 + H2O
ethyl alcohol acetaldehyde acetic acid
Learning Check
Select the product for the oxidation of
CH3CH2CH2OH:
1) CH3CH=CH2
O

2) CO2 + H2O 3) CH3CH2CH
Solution
Select the product for the oxidation of
CH3CH2CH2OH:
[O]
O

3) CH3CH2CH
Reduction
Is a loss of oxygen (O)
or
gain of hydrogen (H)
Reduction
Aldehydes are reduced to 1°
alcohols and ketones are
reduced to 2° alcohols
Alcohols
1°
aldehydes
2°
ketones
Phenols
IUPAC name for benzene with a hydroxyl
group
 Many are used as antiseptics and
OH
disinfectants

Phenol
Phenols in Medicine
OH
OH
OH
OH
OH
CH2CH2CH2CH2CH2CH3
Phenol
Resorcinol
(antiseptic)
4-Hexylresorcinal
(antiseptic)
Ethers


Contain an -O- between two carbon groups
Simple ethers named from -yl names of the
attached groups and adding ether.
CH3-O-CH3
dimethyl ether
CH3-O-CH2CH3
ethyl methyl ether
Ethers as Anesthetics
 Anesthetics inhibit pain signals to the brain
 CH3CH2-O-CH2CH3 used for over a century;
commonly called just ether (Morton, 1846)
 Causes nausea and is highly flammable
 1960s developed nonflammable anesthetics
Cl F F
Cl F H
H-C-C-O-C-H
F F
F
Ethane(enflurane)
H-C-C-O-C-H
HF
H
Penthrane
MTBE

Methyl tert-butyl ether
CH3
CH3-O-C-CH3
CH3

Second in production of organic chemicals

Additive to improve gasoline performance

Use in question with discovery of contaminated water
supplies
Learning Check
Write the structure of the following:
A. 3-pentanol
B. Dimethyl ether
C. 3-methylcyclobutanol
Solution
Write the structure of the following:
OH
|
A. 3-pentanol
CH3CH2CHCH2CH3
B. Dimethyl ether
CH3-O-CH3
CH3
C. 3-methylcyclobutanol
OH
Thiols



Contain the functional group -SH
Named by adding thiol to the name of the
longest carbon chain
Number the -SH group in longer chains
CH3-SH
methanethiol
CH3-CH2SH
SH
ethanethiol
CH3-CH-CH3
2-propanethiol
Thiols



Many thiols have disagreeable odors
Used to detect gas leak
Found in onions, oysters, garlic and oysters
Onions CH3CH2CH2-SH
Garlic CH2= CHCH2-SH
Skunk spray
CH3
1-propanethiol
2-propene-1-thiol
trans-2-butene-1-thiol
CH = CH
CH2SH