timberlake lectureplus 19991 chapter 10 alkanes and aromatic hydrocarbons cycloalkanes aromatic...
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Timberlake LecturePLUS 1999 1
Chapter 10Alkanes and Aromatic
Hydrocarbons
Cycloalkanes
Aromatic Hydrocarbons
Timberlake LecturePLUS 1999 2
Cycloalkanes
Cyclopropane CH2
CH2 CH2
CyclobutaneCH2 CH2
CH2 CH2
Timberlake LecturePLUS 1999 3
More Cycloalkanes
Cyclopentane CH2
CH2 CH2
CH2 CH2
Cyclohexane
CH2
CH2 CH2
CH2 CH2
CH2
Timberlake LecturePLUS 1999 4
Naming Cycloalkanes with Side Groups
Number of Naming
side groups
One Side group name goes in front of the cycloalkane name.
Two Number the ring in the direction that gives the lowest numbers to the side groups.
Timberlake LecturePLUS 1999 5
Cycloalkanes with Side Groups
1,2,4-trimethylcyclohexane
1,2-dimethylcyclopentane
methylcyclopentane
CH3
CH3
CH3
CH3
CH3
CH3
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Learning Check Alk8
CH3
CH3
CH3
CH3
CH3
Timberlake LecturePLUS 1999 7
Solution Alk8
CH3
CH3
CH3
CH3
CH3
1,2-dimethylcyclobutane
methylcyclopropane
1,3-dimethylcyclohexane
CH3
CH3
CH3
CH3
CH3
CH3
CH3
CH3
CH3
CH3
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Aromatic Compounds
Aromatic compounds contain benzene. Benzene C6H6 has 6 C atoms and 6 H Atoms
Two possible ring structures show benzene.H
H
H
H
H
H
H
H
H
H
H
H
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Benzene Structure
The structures for benzene are also written as one formula with a circle within the ring to represented the alternating double bonds.
Benzene
structure
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Aromatic Compounds in Nature and Health
Many aromatic compounds are common in nature and in medicine.
Ibuprofen
CHCOOH
CH3
CH3CHCH2
CH3
Aspirin Vanillin
CHO
OCH3
OH
COOH
COOCH3
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Naming Aromatic Compounds
Aromatic compounds are named with benzene as the parent chain. One side group is named in front of the name benzene.
methylbenzene chlorobenzene
ClCH3
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Naming Aromatic Compounds
When two groups are attached to benzene, the ring is numbered to give the lower numbers to the side groups. The prefixes ortho (1,2), meta (1,3-) and para (1,4-) are also used.
(para-chloromethylbenzene)(meta-dichlorobenzene)(ortho-dimethylbenzene)
1,2-dimethylbenzene 1,3-dichlorobenzene 1-chloro-4-methylbenzene
Cl
CH3
Cl
Cl
CH3
CH3
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Some Common Names
Some substituted benzene rings also use a common name. Then naming with additional more side groups uses the ortho-, meta-, para- system.
(Methylbenzene) (meta-chloromethylbenzene) (hydroxybenzene) Toluene meta-chlorotoluene phenol
OH
Cl
CH3CH3
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Learning Check Alk9
Select the names for each structure:
1. Chlorocyclohexane2. Chlorobenzene3. 1-chlorobenzene
1. Meta-methyltoluene2. Meta-dimethylbenzene3. 1,3-dimethylbenzene
CH3
CH3
Cl
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Solution Alk9
Select the names for each structure:
2. Chlorobenzene
1. Meta-methyltoluene
2. Meta-dimethylbenzene
3. 1,3-dimethylbenzene
CH3
CH3
Cl
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Learning Check Alk10
Write the structural formulas for each of the following:
A. 1,3-dichlorobenzene
B. Ortho-chlorotoluene
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Solution Alk10
Write the structural formulas for each of the following:
A. 1,3-dichlorobenzene
B. Ortho-chlorotoluene
Cl
Cl
CH3
Cl
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Learning Check Alk11
Identify the organic family for each:
CH3CH2CH3
B.
C.
A.
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Solution Alk11
Identify the organic family for each:
alkane
cycloalkane
aromatic
CH3CH2CH3
B.
C.
A.
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Fused Benzene Rings
Naphthalene
3,4-Benzpyrene
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Carcinogens
• Fused ring of benzene cause cancer• Contain four or more fused rings• Present in tobacco smoke, auto exhaust,
and burned food• The more a person smokes, the greater
the risk of developing cancer