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Chemistry 2100
Lecture 4
ALCOHOLSALCOHOLSETHERSETHERSTHIOLSTHIOLS
thiol / mercaptan(sulfhydryl)
alcohol
HS
R
ether
R'O
R
HO
R
Common Nomenclature
• alkyl "alcohol"
• dialkyl "ether"
IUPAC Nomenclature
• "e" "ol"
• locator numbers
Alcohols
Alcohol:Alcohol: A compound that contains an -OHOH (hydroxyl) group(hydroxyl) group bonded to a tetrahedral carbon.– Methanol, CH3OH, is the simplest alcohol.
Nomenclature1. 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 -ee to -olol 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 dioldiol, one containing three hydroxyl groups as a trioltriol, 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 glycolsglycols.CH3CHCH2
HO OHCH2CH2OH OH
CH2CHCH2
OH OHOH1,2-Ethanediol
(Ethylene glycol)1,2-Propanediol
(Propylene glycol)1,2,3-Propanetriol
(Glycerol, Glycerin)
Physical PropertiesAlcohols 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.
CH3OH 65° CH3CH2CH2OH 97°
CH3CH3 -88° CH3CH2CH2CH3 0°
CH3Cl -24° CH3CH2CH2Cl 46°
PhOH 182° CH3CH2CH2CH2OH 118°
PhCH3 110° (CH3)2CHCH2OH 108°
PhCl 132° (CH3)3COH 83°
boiling points (°C)
solubility (g / 100 mL H2O)
∞
∞
8.3
2.4
0.6
0.05
7.8
10.0
∞
3.6
CH3CH2OH
CH3CH2CH2OH
CH3CH2CH2CH2OH
CH3CH2CH2CH2CH2OH
CH3CH2CH2CH2CH2CH2OH
CH3CH2CH2CH2CH2CH2CH2CH2OH
CH3CH2OCH2CH3
(CH3)2CHCH2OH
(CH3)3COH
C6H11OH
zymase
sucrose ethanol
2O
2O
C12H22O11 + H
4 C2H5OH + 4 CO
Preparing AlcoholsFermentation
Alkene Hydration
+H2SO4
H OH
H2OCC C C
OHH
H
H H
H H
H H
H
DehydrationCH3CH2OH
H2SO4 CH2=CH2 H2O+Ethanol Ethylene
180°C
OHH2SO4 H2O140°C
Cyclohexanol Cyclohexene
+
CH3CCH3
OH
CH3H2SO4 CH3C=CH2
CH3
H2O50°C
2-Methyl-2-propanol (tert -Butyl alcohol)
2-Methylpropene (Isobutylene)
+
Oxidation of Alcohols
(1°)
(2°)
N
H H
NAD +
H+
CH3 C H
O
NAD H
Ad Ad
CH3
H
C
O
H
H
N
H
••
[O]
N
H H
NAD +
H+
CH3 C H
O
NAD H
Ad Ad
CH3
H
C
O
H
H
N
H
••
[O]
N
H H
NAD +
H+
CH3 C H
O
NAD H
Ad Ad
CH3
H
C
O
H
H
N
H
••
[O]
N
H H
NAD +
H+
CH3 C H
O
NAD H
Ad Ad
CH3
H
C
O
H
H
N
H
••
[O]
N
H H
NAD +
H+
CH3 C H
O
NAD H
Ad Ad
CH3
H
C
O
H
H
N
H
••
[O]
N
H H
NAD +
H+
CH3 C H
O
NAD H
Ad Ad
CH3
H
C
O
H
H
N
H
••
[O]
N
H H
NAD +
H+
CH3 C H
O
NAD H
Ad Ad
CH3
H
C
O
H
H
N
H
••
[O]
N
H H
NAD +
H+
CH3 C H
O
NAD H
Ad Ad
CH3
H
C
O
H
H
N
H
••
[O]
Ethers
Common Nomenclature
• dialkyl "ether"• dialkyl "ether"
• "alkoxy"
IUPAC Nomenclature
(diethyl) etherbp 36°C
7.8 g/100 mL
1-butanol bp 118°C
8.3 g/100 mL
pentanebp 36°C
H C C O C C H
H
H
H
H
H
H
H
H
H C C C C C H
H
H
H
H
H
H
H
H
H
H
H C C C C O H
H
H
H
H
H
H
H
H
isoflurane
F C
F
O
F
C C
Cl
H
F
F
F
halothane enflurane
F C C
F
F
Br
Cl
H
F C
H
O
F
C C
F
F
Cl
F
H
Anesthetics
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)
[O]R S R'
O
••
• •
• •R S R'
[O]R S R'
O
Osulfoxidesulfide (thioether)
sulfone
Oxidation
cysteine
C OH
O
CH
NH2
CH2SH
S S
S S
[H]
[O]
SH
SH
SH
SH
S
S
S
S
S S
S S
[H]
[O]
S
S
S
S
SH
SH
SH
SH
[H]
[O]
S
S
S
S
SH
SH
SH
SH
S S
S S
-helix
-helix
-helix
-helix
-helix
-helix
-helix
-helix
-helix
-pleated sheet
-helix
-helix-pleated sheet
-pleated sheet
salt bridge
NH3
+
-helix
-helix-pleated sheet
-pleated sheet
C-O
O
hydrogenbond
CH2 O
H
CH2O
H
salt bridge
NH3
+
-helix
-helix-pleated sheet
-pleated sheet
C-O
O
hydrogenbond
CH2 O
H
CH2O
H
NH
H
C
OH
O
hydrogenbond
salt bridge
NH3
+
-helix
-helix-pleated sheet
-pleated sheet
C-O
O
hydrogenbond
CH2 O
H
CH2O
H
NH
H
C
OH
O
hydrogenbond
salt bridge
NH3
+
CH2
HO
hydrophilicinteractionto water
CH2
C
NH2
O
CH2
HO
-helix
-helix-pleated sheet
-pleated sheet
C-O
O
CH2
CH2
hydrophobicinteraction
hydrogenbond
CH2 O
H
CH2O
H
NH
H
C
OH
O
hydrogenbond
salt bridge
NH3
+
CH2
HO
hydrophilicinteractionto water
CH2
C
NH2
O
CH2
HO
-helix
-helix-pleated sheet
-pleated sheet
C-O
O
CH
CH3 CH3
CH3
CH2
CH2
hydrophobicinteraction
hydrogenbond
CH2 O
H
CH2O
H
NH
H
C
OH
O
hydrogenbond
salt bridge
NH3
+
CH2
HO
hydrophilicinteractionto water
CH2
C
NH2
O
CH2
HO
-helix
-helix-pleated sheet
-pleated sheet
C-O
O
CH
CH3 CH3
CH3
CH2
CH2
hydrophobicinteraction
S
S
S
Sdisulfide
bond
hydrogenbond
CH2 O
H
CH2O
H
NH
H
C
OH
O
hydrogenbond
salt bridge
NH3
+
CH2
HO
hydrophilicinteractionto water
CH2
C
NH2
O
CH2
HO
-helix
-helix-pleated sheet
-pleated sheet
C-O
O
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