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How are unbranched alkanes named according to the number of carbon atoms?
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organic compound
The structures of organic compounds can be depicted in condensed, expanded, and three-dimensional structural formulas.
According to the International Union of Pure and Applied Chemistry (IUPAC) rules, unbranched alkanes are named based on the number of carbon atoms in their chain.1
- Small chains: The names methane, ethane, and propane are retained for the first three members of the series (containing one, two, and three carbons, respectively).1
- Four carbons and beyond: For chains with four or more carbon atoms, the name consists of a Latin or Greek stem that corresponds to the number of carbons, followed by the suffix -ane.1
Notably, the n- prefix is not used in systematic IUPAC nomenclature for unbranched alkanes; for example, a four-carbon chain is simply called butane. These compounds form a homologous series where each member differs from the next by the successive addition of a group.1