Quick Guide to Organic Nomenclature
Pick longest carbon chain as base, assign
numbers so that they are as low as possible
Are two compounds the same?
Can they be “superimposed”?
Yes  same compound
No  different compounds
Are two compounds the same?
Neither of these can be superimposed with any of the others
Therefore, each is different from one another and from the
other two.
Flip over - same structure
Therefore, these are the same compound
All have the same molecular formula (C11H24O).
Therefore, the different compounds are structural isomers.
More complex alkanes
1. Pick longest carbon chain as base (or, perhaps, cycloalkane or aromatic).
2. Determine substituents; assign numbers so that you have the lowest set of numbers.
3. Name is list of substituents in alphabetical order, preceeded by number.
More complex alkanes
1. Pick longest carbon chain as base (or, perhaps, cycloalkane or aromatic).
2. Determine substituents; assign numbers so that you have the lowest set of numbers.
3. Name is list of substituents in alphabetical order, preceeded by number.
Longest carbon chain = 8 : thus, it is an octane
Substituents: methyl, chloro, fluoro
Either 2, 5, 6 or 3, 4, 7 – go with 2, 5, 6
5-chloro-6-fluoro-2-methyloctane
All numbers and letters separated by dash.
Chain = 9: nonane
Base = nonylamine (NH2 – amine)
Substituents: 2 methyls
3,5-dimethyl-5-nonylamine
Chain = not applicable
Base = cyclohexanol (6 membered ring of carbons)
Substituents: bromo, amino, isopropyl
3-amino-2-bromo-5-isopropylcyclohexanol
Chain = 12: dodecane
Alkene  dodecene
Base = dodecenol (alcohol)
Substituents: chloro, phenyl (benzene ring), n-propyl
4-chloro-7-phenyl-6-n-propyldodec-3-en-2-ol