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Unformatted text preview: e prefix cyclo- to the name of the corresponding
alkane. Naming Cycloalkanes
Identify and name substituents as before.
For one substituent no numbers are used. Naming Cycloalkanes
For multiple substituents the locations must be specified.
Number the carbon atoms of the ring in the direction that
gives the lowest number to the substituents at the first
point of difference.
First substituent is on C1 by default. Naming Cycloalkanes
If the ring has fewer carbons than the alkyl group attached
to it then the ring is the substituent. 2.19
Sources of Alkanes and Cycloalkanes
Sources Sources of Alkanes and Cycloalkanes
Natural is mainly methane with ethane and propane.
Petroleum is a liquid mixture containing approximately 150
hydrocarbons. Half of these are alkanes or cycloalkanes.
Distillation of crude oil gives fractions based on boiling point. Petroleum Refining
The yield of the more useful petroleum fraction used as
automotive fuel is increased by two processes:
Cracking. Cracking is the cleavage of carbon–carbon bonds
in high molecular weight alkanes induced by heat (thermal
cracking) or with catalysts (catalytic cracking).
Reforming. Reforming converts the hydrocarbons in
petroleum to aromatic hydrocarbons and highly branched
alkanes, both of which are better automotive fuels than
unbranched alkanes and cycloalkanes. Other Natural Sources of Alkanes
Solid n-alkanes are waxy and coat the outer surface of many
living things to prevent loss of water. Examples include:
Pentacosane (CH3(CH2)23CH3 is found in the waxy outer
layer of many insects.
Hentriacontane is a component of beeswax and the outer
layer of leaves of tobacco, peach trees and others.
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- Fall '08