Branched Alkanes
Substituents Any hydrogen in a hydrocarbon chain can be substituted with another hydrocarbon group
Substituents The substituted hydrocarbon group is called an alkyl group Suffix: -yl: hydrocarbon group
Branched Chains When an alkane chain gets another hydrocarbon group substituted onto it Branches: sidechains
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
) Find the longest continuous carbon chain & name it as the main chain ) 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
) 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
) 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
) 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
) Name the sidechains or groups in alphabetical order, but ignore the prefixes when doing so Examples: ethyl comes before dimethyl, e < m
) 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 compounds in problem 11-5 on page 315
Name the organic compound on the board
Drill: Name CH3 CH2 H3C-CH-CH2-CH-CH-CH3 CH3 CH2
Deriving Structures from Names Draw the main chain first Look the name ending Draw the branches Look the # & group name
Draw: 3,4-diethyl-2-methyloctane 2,3,5-trimethylhexane 5-butyl-3-ethyl-2,6,8-trimethyl-4-propyldecane
5-butyl-3-ethyl-2,6,8,9-tetramethyl-4,7-dipropyldecane Drill: Draw: 5-butyl-3-ethyl-2,6,8,9-tetramethyl-4,7-dipropyldecane
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
Draw & name all the possible structural isomers for C7H16
Draw & name all the possible structural isomers for C6H14
Drill: Name: C-C-C C C-C-C-C-C-C-C C C-C
Review
Identify Organic terms Organic prefixes Organic suffixes
Drill: Name the organic compounds on the board:
Draw the organic compounds on the board:
Draw & Name isomers of: C8H18