SCH 4U Organic Day 6
Alcohols and Ethers
Assignment
Page 41 # 1-3
42 # 4-6
49 # 7-9
Compounds with Oxygen
Atoms
Alcohols -OH hydroxyl
CH3-OH
CH3CH2-OH
OH
OH
Phenols
Ethers
-O-
CH3-O-CH 3
Alcohols and Ether
Naming Alcohols
n A carbon compound that contain -OH
(hydroxyl) group
n In IUPAC name, the -e in alkane name is
replaced with -ol.
CH4 methane
CH3OH
methanol
(methyl alcohol)
CH 3CH 3 ethane
CH 3CH2OH ethanol
(ethyl alcohol )
More Names of Alcohols
n IUPAC names for longer chains number the
chain from the end nearest the -OH group.
CH 3CH 2CH 2OH
1-propanol
OH
CH3CHCH 3
CH3
2-propanol
OH
CH 3CHCH 2CH2CHCH 3
5-methyl-2-hexanol
IUPAC Substitutive Nomenclature
An IUPAC name may have up to 4 features: locants, prefixes,
parent compound and suffixes
Numbering generally starts from the end of the chain which is
closest to the group named in the suffix
Double bonds and alcohols
Alkenols
P The hydroxyl has highest priority (so far)
P -OH is given the lowest possible number
Double bonds and alcohols
Alkenols
1
2
3
Classification of Alcohols
Primary (1º)
H
Secondary (2º )
CH3
CH 3-C-OH
CH 3-C-OH
H
H
1C
attached
to C-OH
2C
attached
to C-OH
Tertiary (3º)
CH 3
CH 3-C-OH
CH 3
3C
attached
to C-OH
l
3o alcohols are much less reactive than 1o or 2o
alcohols in oxidation reactions.
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
1,2,3-propanetriol
Phenols
l IUPAC name for benzene with a hydroxyl
group
OH
l Many are used as antiseptics and
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.
CH 3-O-CH3
dimethyl ether (methoxymethane)
CH 3-O-CH2CH3
ethyl methyl ether (methoxyethane)
IUPAC Naming of Ethers
Identify the smaller chain attached to the -OName this alkyl as a prefix, change the -yl to -oxy
Name the longer chain on -oxy as suffix
CH3-O-CH 3
methoxymethane
CH 3-O-CH2 CH 3
methoxyethane
Ethers as Anesthetics
l Anesthetics inhibit pain signals to the brain
l CH3CH2-O-CH2CH3 used for over a century
(Morton, 1846)
l Causes nausea and is highly flammable
l 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
Alcohol functional groups are
polar
Hydrogen bonding is possible (like water)
The more red an area is, the higher the
electron density and the more blue an area is,
the lower the electron density.
The hydroxyl O atom is a region of high
electron density (red) due to the lone pairs.
Physical Properties of Alcohols
(R-OH)
P Molecules of alcohols can hydrogen bond
to each other
P Alcohols have considerably higher
boiling points than ethers
Physical Properties of Ethers (R-O-R’)
P Molecules of ethers cannot hydrogen bond to
each other (no H attached to O)
P Ether boiling points are similar to
hydrocarbons of the same molecular weight
P Ethers form dipole-dipole attractions
P Small carbon chain ethers are soluble in
water
Dehydration of Alcohols
P Alcohols can be made by addition of water to
alkenes
P Alkenes can be made by dehydration of
alcohols
P Tertiary alcohols are easier to dehydrate than
primary alcohols
Synthesis of Ethers
P Primary alcohols dehydrate to produce
ethers at low temperatures
P Alcohols dehydrate to produce alkenes at
higher temperatures
P 2o and 3o alcohols form alkenes more than
ethers
Learning Check Al1
Classify each as an alcohol (1), phenol (2), or
an ether (3):
A. _____ CH 3CH2-O-CH3
OH
B. _____
CH3
C. _____ CH 3CH2OH
Solution Al 1
Classify each as an alcohol (1), phenol (2), or
an ether (3):
A. __3__ CH 3CH2-O-CH3
OH
B. _ 2__
CH3
C. __1__ CH3CH2OH
Learning Check Al 2
Name the following alcohols:
A.
OH
CH3CHCHCH 2CH3
CH3
OH
B.
Solution Al 2
Name the following alcohols:
A.
OH
CH3CHCHCH 2CH3
3-methyl-2-pentanol
CH 3
OH
B.
cyclobutanol