•Drill: Give the molecular
formula & the condensed,
skeletal, and complete
structures of a hydrocarbon
with the same # of carbons
as the # of letters in your
first name.
Branched
Alkanes
•Any hydrogen in a
hydrocarbon chain
can be substituted
with another
hydrocarbon group
HHH
H-C-C-C-H
HHH
propane
HHH
H-C-C-C-H
HHH
propane
HHH
H-C-C-C-H
H CH H
_____propane
3
Alkyl Groups
•The hydrocarbon group
that replaces the H is
called an alkyl group
•Suffix: -yl:
hydrocarbon group
•1 =
•2 =
•3 =
•4 =
•5 =
Alkyl Groups
methyl 6 =
ethyl
7=
propyl 8 =
butyl
9=
pentyl 10 =
hexyl
heptyl
octyl
nonyl
decyl
Branched Chains
•When an alkane chain
gets another hydrocarbon
group substituted onto it
•Branches: alkyl groups or
sidechains
Drill: Draw
C8H18 using 4
different
methods.
Branched Chains
C
C C C C C C
C
C C
Naming
Branched
Chains
Drill: Name Each:
H3C-CH2-CH3
C-C-C-C-C
1) Find the longest
continuous carbon chain
& name it as the main
chain. The final name will
end with the naming of
the main chain
• C
Hexane
•C C C C C C
• C
C C
2) Number each carbon
in the chain; so that, the
side chains will be
connected to the lowest
possible numbers on
the carbons
• C
Hexane
1
2
3
4
5
6
•C C C C C C
• C
C C
3) Name the side chains
or substituted groups,
& precede them with
the # of the carbon they
are connected to & a
dash
C 2-methyl
1
2
3
4
5
6
C C C C C C
C
C C
2-methyl
4-ethyl
4) If identical groups
appear more than once,
use prefixes: di for 2, tri
for 3, tetra for 4, penta for
5, etc Examples:
dimethyl, tripropyl, etc
C 2,2-dimethyl
1
2
3
4
5
6
C C C C C C
C
C C
4-ethyl
5) Name the sidechains or
groups in alphabetical
order, but ignore the
prefixes when doing so
· Examples: ethyl comes
before dimethyl, e < m
6) Separate numbers with
commas, use hyphens
between words &
numbers, and write the
alkanes as one word
· Example: dimethylhexane
C
CCCCCC
C C C
4-ethyl-2,2-dimethylhexane
Name the organic
compound on the
board
Drill: Name
CH3
CH2
H3C-CH-CH2-CH-CH-CH3
CH3
CH2
CH3
Student
Practice
Problems
1)
H3C-CH2
CH2-CH2-CH3
CH2-CH-CH-CH2-CH-CH2-CH3
CH2-CH2-CH3
1)
H3C-CH2
CH2-CH2-CH3
CH3-CH-CH-CH2-CH-CH2-CH3
CH2-CH2-CH3
1)
H3C-CH2
CH2-CH2-CH3
CH3-CH-CH-CH2-CH-CH2-CH3
CH2-CH2-CH3
1)
H3C-CH2
CH2-CH2-CH3
CH3-CH-CH-CH2-CH-CH2-CH3
CH2-CH2-CH3
6-ethyl-3-methyl-4-propylnonane
2)
C
C-C
C-C-C
C-C-C
C C
C C
2)
C
C-C
C-C-C
C-C-C
C C
C C
2)
C
C-C
C-C-C
C-C-C
C C
C C
C 3,4-diethylC-C 2-methyloctane
C-C-C
C-C-C
C C
C C
2)
3)
3)
3)
3)
3-ethyl-2,5,7-trimethyl-4,6-dipropyldecane
Deriving Structures
from Names
• Draw the main chain first
–Look to the name ending
• Draw the branches
–Look to the # & group name
Draw:
• 3,4-diethyl-2-methyloctane
• 2,3,5-trimethylhexane
• 5-butyl-3-ethyl-2,6,8trimethyl-4-propyldecane
Draw:
5butyl-3-ethyl-2,6,8,9tetramethyl-4,7dipropyldecane
Drill: Name the following:
C-C-C C-C-C
C-C-C-C-C-C-C
C-C-C-C
Draw the Following:
• 4,5-diethyl-3,4,5trimethyloctane
• 3,3,4,4,5,5-hexaethylheptane
Isomers
•Compounds that have
the same chemical
formula, but different
shapes
Types of Isomers
•Structural or skeletal
•Geometric or cis/trans
•Functional
•Positional
•Optical
Structural
Isomers
•When there are
differences in the
carbon chains
Structural Isomers
C-C-C-C-C
C
C-C-C-C
C
C-C-C
C
Structural Isomers
C-C-C-C-C
C
C-C-C-C
C
C-C-C
C
Structural Isomers
Pentane
methyl
butane
dimethyl
propane
Draw & name all
the possible
structural isomers
for C6H14
Draw & name all
the possible
structural isomers
for C8H18
Draw & name all
the possible
structural isomers
for C7H16
Drill: Draw &
name all the
possible structural
isomers for C6H14
This Week’s
Schedule
• Lab Tomorrow
• Review Thursday
• Test Friday
Name:
C-C-C C
C-C-C-C-C-C-C
C C-C
C-C-C C
C-C-C-C-C-C-C
C C-C
C-C-C C
C-C-C-C-C-C-C
C C-C
3,5-diethyl-3,5dimethyloctane
Draw the Following:
• 3,5-diethyl-2,4,6trimethyloctane
• 5-butyl-3-ethyl-2,6,6,8tetramethyl-4-propylnonane
Draw the condensed,
complete, skeletal, &
stick structures for:
•3-ethyl-2,2dimethylpentane
Draw & name all
the possible
structural isomers
for C9H20
Drill: Name &
describe 5 organic
prefixes & 4
organic suffixes
Test on
Alkanes
tomorrow
Review
Identify
•Organic terms
•Organic prefixes
•Organic suffixes
Organic Prefixes
•1 =
•2 =
•3 =
•4 =
•5 =
methethpropbutpent-
6=
7=
8=
9=
10 =
hexheptoctnondec-
Name:
CH3-CH2
H3C-CH-CH2-C-CH2-CH3
CH3-CH2
CH3
CH3-CH2
H3C-CH-CH2-C-CH2-CH3
CH3-CH2
CH3
CH3-CH2
H3C-CH-CH2-C-CH2-CH3
CH3-CH2
CH3
3-ethyl-3,5-dimethylheptane
CH3-CH2
H3C-CH-CH2-C-CH2-CH3
CH3-CH2
CH3
Name:
C-C
C-C
C-C-C-C-C-C-C-C-C
C CC
C
C-C
C-C
C-C-C-C-C-C-C-C-C
C CC
C
C-C
C-C
C-C-C-C-C-C-C-C-C
C CC
C
6,7-diethyl-3,4,7-trimethyldecane
C-C
C-C
C-C-C-C-C-C-C-C-C
C CC
C
Name:
5-ethyl-2,4,6,7tetramethylnonane
Name:
5-butyl-2,3,7,8-tetramethyl-6-propyldecane
Draw the complete
structure of:
3-ethyl-2-methylpentane
Draw the condensed
structure of:
3-ethyl-2,4,5-trimethylhexane
Draw a skeletal
structure of:
Octamethylhexane
Draw a stick
structure of:
5-butyl-3-ethyl-2,4,6,8tetramethyl-4-propyl
decane
Draw & Name
10 isomers of:
C8H18
Draw an optical
isomer of:
C
C
C-C-C-C-C-C-C
C