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Chemistry 2100
Lecture 4
ALCOHOLS
ETHERS
THIOLS
O
R
O
H
alcohol
R
S
R'
ether
R
H
thiol / mercaptan
(sulfhydryl)
Common Nomenclature
IUPAC Nomenclature
• alkyl "alcohol"
• dialkyl "ether"
• "e"
"ol"
• locator numbers
Alcohols
Alcohol: A compound that contains an -OH
(hydroxyl) group bonded to a tetrahedral carbon.
– Methanol, CH3OH, is the simplest alcohol.
Nomenclature
1. Select the longest carbon chain that contains the -OH group
as the parent alkane and number it from the end that gives
the -OH the lower number.
2. Change the ending of the parent alkane from -e to -ol and use
a number to show the location of the -OH group; for cyclic
alcohols, the carbon bearing the -OH group is carbon-1.
3. Name and number substituents and list them in alphabetical
order.
Nomenclature
– In the IUPAC system, a compound containing two hydroxyl
groups is named as a diol, one containing three hydroxyl
groups as a triol, and so forth.
– IUPAC names for diols, triols, and so on retain the final "-e"
in the name of the parent alkane.
– We commonly refer to compounds containing two hydroxyl
groups on adjacent carbons as glycols.
CH2 CH2
OH OH
1,2-Eth anediol
(Eth ylen e glycol)
CH3 CHCH2
HO OH
1,2-Propan ediol
(Propylene glycol)
CH2 CHCH2
OH OHOH
1,2,3-Propan etriol
(Glycerol, Glycerin)
Physical Properties
Alcohols are polar molecules.
– The C-O and O-H bonds are both polar covalent.
Physical Properties
In the liquid state,
alcohols associate
by hydrogen
bonding.
boiling points (°C)
CH3OH
65°
CH3CH2CH2OH
97°
CH3CH3
-88°
CH3CH2CH2CH3
0°
CH3Cl
-24°
CH3CH2CH2Cl
PhOH
182°
CH3CH2CH2CH2OH
118°
PhCH3
110°
(CH3)2CHCH2OH
108°
PhCl
132°
(CH3)3COH
46°
83°
solubility (g / 100 mL H2O)
CH3CH2OH
∞
CH3CH2CH2OH
∞
CH3CH2CH2CH2OH
8.3
CH3CH2CH2CH2CH2OH
2.4
CH3CH2CH2CH2CH2CH2OH
0.6
CH3CH2CH2CH2CH2CH2CH2CH2OH
0.05
CH3CH2OCH2CH3
7.8
(CH3)2CHCH2OH
10.0
(CH3)3COH
∞
C6H11OH
3.6
Preparing Alcohols
Fermentation
+
C12H22O11
H2O
zymase
4 C2H5OH
+
4 CO2O
ethanol
sucrose
Alkene Hydration
H
+
C C
H
H H
H
H
H2 O
H OH
H2S O4
H
C C
H OH
H
Dehydration
CH3 CH2 OH
Ethan ol
OH
Cycloh exanol
H2 SO4
180°C
H2 SO4
140°C
CH2 =CH2 + H2 O
Ethylen e
+ H2 O
Cyclohexen e
CH3
CH3
H2 SO4
CH3 CCH3
CH3 C=CH2 + H2 O
50°C
OH
2-Meth yl-2-p ropanol
2-Methylpropene
(Isobutylene)
(t ert -Butyl alcoh ol)
Oxidation of Alcohols
(1°)
(2°)
H+
CH3
O
H
C
H
H
O
[ O]
H
CH3
C
H
H
H
••
N
N
Ad
Ad
NAD +
NAD H
H+
CH3
O
H
C
H
H
O
[ O]
H
CH3
C
H
H
H
••
N
N
Ad
Ad
NAD +
NAD H
H+
CH3
O
H
C
H
H
O
[ O]
H
CH3
C
H
H
H
••
N
N
Ad
Ad
NAD +
NAD H
H+
CH3
O
H
C
H
H
O
[ O]
H
CH3
C
H
H
H
••
N
N
Ad
Ad
NAD +
NAD H
H+
CH3
O
H
C
H
H
O
[ O]
H
CH3
C
H
H
H
••
N
N
Ad
Ad
NAD +
NAD H
H+
CH3
O
H
C
H
H
O
[ O]
H
CH3
C
H
H
H
••
N
N
Ad
Ad
NAD +
NAD H
H+
CH3
O
H
C
H
H
O
[ O]
H
CH3
C
H
H
H
••
N
N
Ad
Ad
NAD +
NAD H
H+
CH3
O
H
C
H
H
O
[ O]
H
CH3
C
H
H
H
••
N
N
Ad
Ad
NAD +
NAD H
Ethers
Common Nomenclature
IUPAC Nomenclature
• dialkyl "ether"
• dialkyl "ether"
• "alkoxy"
H H
H H H H H
H
C C C C C H
H H H H H
pentane
bp 36°C
H
C
H H
C O C
H H
C H
H H
(diethyl) ether
bp 36°C
7.8 g/100 mL
H H H H
H
C C C C O H
H H H H
1-butanol
bp 118°C
8.3 g/100 mL
Anesthetics
F Cl
F
C C Br
F
H
halothane
F
F
F
F
C O C C Cl
H
F
e nflurane
H
F
F
Cl F
C O C C F
F
H
isoflurane
F
Thiols / Mercaptans
Naming thiols
Alkane + thiol
1-propanethiol
2-propene-1-thiol
CH3CH2OH (bp 78°C)
CH3OCH3 (bp -24°C)
CH3CH2SH (bp 35°C)
CH3SCH3 (bp 37°C)
Oxidation
O
O
R
••
S
R'
••
sulfide (thioether)
[ O]
R S
••
R'
sulfoxide
[ O]
R
S
O
sulfone
R'
O
H S CH2
CH
NH2
cysteine
C OH
S
S
S
S
[ H]
SH
SH
SH
SH
[ O]
S S
S S
S
S
S
S
[ H]
SH
SH
SH
SH
[ O]
S S
S S
S
S
S
S
[ H]
SH
SH
SH
SH
[ O]
S S
S S
-helix
-helix
-helix
-helix
-helix
-helix
-helix
-helix
-helix
-pleated sheet
-pleated sheet
-helix
-pleated sheet
-helix
-pleated sheet
salt bridge
O
-O
C
NH3+
-helix
-pleated sheet
-helix
-pleated sheet
salt bridge
O
-O
C
NH3+
CH2
O
H
-helix
hydrogen
bond
O
H
CH2
-pleated sheet
-helix
-pleated sheet
hydrogen
bond
H N
OH
H
C O
salt bridge
O
-O
C
NH3+
CH2
O
H
-helix
hydrogen
bond
O
H
CH2
-pleated sheet
-helix
hydrophilic
interaction
to water
-pleated sheet
HO
CH 2
N H2
HO
O
hydrogen
bond
C
C H2
H N
OH
CH2
H
C O
salt bridge
O
-O
C
NH3+
CH2
O
H
-helix
hydrogen
bond
O
H
CH2
-pleated sheet
-helix
hydrophilic
interaction
to water
-pleated sheet
-helix
HO
CH 2
CH2
N H2
HO
O
hydrogen
bond
C
C H2
H N
OH
CH2
H
hydrophobic
interaction
C O
salt bridge
CH2
O
-O
C
NH3+
CH2
O
H
-helix
hydrogen
bond
O
H
CH2
-pleated sheet
hydrophilic
interaction
to water
-pleated sheet
-helix
HO
CH 2
CH2
N H2
HO
O
hydrogen
bond
C
C H2
H N
OH
CH2
H
hydrophobic
interaction
CH3
C O
salt bridge
CH2
O
-O
C
NH3+
CH2
O
H
-helix
hydrogen
bond
O
H
CH
CH3 CH3
CH2
-pleated sheet
hydrophilic
interaction
to water
-pleated sheet
-helix
HO
CH 2
CH2
N H2
HO
O
hydrogen
bond
C
C H2
H N
OH
CH2
CH
CH3 CH3
hydrophobic
interaction
H
CH3
C O
salt bridge
O
-O
S
C
S
NH3+
CH2
CH2
disulfide
bond
S
S
O
H
-helix
hydrogen
bond
O
H
CH2
-pleated sheet