•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

H H HH-C-C-C-H

H H Hpropane

H H HH-C-C-C-H

H H Hpropane

H H HH-C-C-C-H

H CH3 H_____propane

Alkyl Groups•The hydrocarbon group that replaces the H is called an alkyl group

•Suffix: -yl: hydrocarbon group

Alkyl Groups•1 = methyl 6 = hexyl

•2 = ethyl 7 =heptyl

•3 = propyl 8 = octyl

•4 = butyl 9 =nonyl

•5 = pentyl 10 =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•C1 C2 C3 C4 C5 C6

• 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

C1 C2 C3 C4 C5 C6

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

C1 C2 C3 C4 C5 C6

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

C C C C C C

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

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

1)

C C-CC-C-C C-C-C C C C C

2)

C C-CC-C-C C-C-C C C C C

2)

C C-CC-C-C C-C-C C C C C

2)

C C-CC-C-C C-C-C C C C C

3,4-diethyl- 2-methyloctane

2)

3)

3)

3)

3-ethyl-2,5,7-trimethyl-4,6-dipropyldecane

3)

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-2,6,8-trimethyl-4-propyldecane

Draw:5butyl-3-ethyl-2,6,8,9-tetramethyl-4,7-dipropyldecane

Drill: Name the following:

C-C-C-C-C-C-CC-C-C

C-C-C-C

C-C-C

Draw the Following:

• 4,5-diethyl-3,4,5-trimethyloctane

• 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 dimethyl butane 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-3,5-dimethyloctane

Draw the Following:• 3,5-diethyl-2,4,6-

trimethyloctane

• 5-butyl-3-ethyl-2,6,6,8-tetramethyl-4-propylnonane

Draw the condensed, complete, skeletal, & stick structures for:

•3-ethyl-2,2-dimethylpentane

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 = meth- 6 = hex-

•2 = eth- 7 = hept-

•3 = prop- 8 = oct-

•4 = but- 9 = non-

•5 = pent- 10 = dec-

Name:

H3C-CH-CH2-C-CH2-CH3

CH3-CH2

CH3CH3-CH2

H3C-CH-CH2-C-CH2-CH3

CH3-CH2

CH3CH3-CH2

H3C-CH-CH2-C-CH2-CH3

CH3-CH2

CH3CH3-CH2

3-ethyl-3,5-dimethylheptane

H3C-CH-CH2-C-CH2-CH3

CH3-CH2

CH3CH3-CH2

Name:

C-C-C-C-C-C-C-C-CC-C

CC

C-C

C C

C-C-C-C-C-C-C-C-CC-C

CC

C-C

C C

C-C-C-C-C-C-C-C-CC-C

CC

C-C

C C

C-C-C-C-C-C-C-C-CC-C

CC

C-C

C C

6,7-diethyl-3,4,7-trimethyldecane

Name:

5-ethyl-2,4,6,7-tetramethylnonane

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-2,4,6,8-tetramethyl-4-propyldecane

Draw & Name 10 isomers of:

C8H18

Draw an optical isomer of:

C-C-C-C-C-C-CC

C C