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How is the longest carbon chain used to name a branched alkane?
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organic compound
The structures of organic compounds can be depicted in condensed, expanded, and three-dimensional structural formulas.
In the systematic nomenclature of organic compounds, branched alkanes are named based on the longest continuous chain of carbon atoms in the molecule, which serves as the parent structure.
To name the compound, you identify this longest chain and use the name of the corresponding unbranched alkane as the base. For example, if the longest chain contains seven carbon atoms, the compound is named as a derivative of heptane. The positions of any substituents, such as alkyl groups, are then specified using a locant—a number obtained by numbering the carbons in the parent chain starting from the end closest to the first branch. This ensures that the substituents are assigned the lowest possible numbers.1