Branched Chains and Isomerism

Extended chain (pentane) CH3 Single branch (iso-pentane)  

The name pentane derives from the Greek pente, meaning five, indicating that the molecule has five carbon atoms. The other names still use the term pentane, with a prefix iso or neo, trying to convey the fact that these are isomeric molecules. Naming the isomers can become cumbersome when the number of isomers increases. For this reason, chemists have created a standard naming system.  

The principles of creating alkane isomers are clear by now and can be summarized as follows  

Using only CHj fragments with two CH3 caps creates extended chains. Adding a CH fragment creates a chain with a single branch. 

Adding a C fragment to the construction process creates two branches. Depending on the total number of carbons, one can use a few branching fragments to create more isomers. 

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