IUPAC nomenclature of acyclic alkanes

Alkanes are those hydrocarbons which have only single C-C bonds. Acyclic alkanes are those alkanes which do not contain any cycle (ring) of carbon atoms. Their molecular formula is of the form CnH2n+2 (where n is an integer).

I am explaining the IUPAC (International Union of Pure and Applied Chemists) for acyclic alkanes. To name an acyclic alkane as per IUPAC nomenclature, carry out the following steps:-


Step 1. Find the longest chain of C atoms in the hydrocarbon. The longest chain means the chain which contains the greatest number of C atoms. If there is only one chain, then treat that chain as the longest.
Note that it is not necessary for the chain to be straight; there can be bends. If there are more than one longest chain, then select any one of them. Sometimes there may be confusion on deciding whether some C atoms belong to the same chain or not. To get the answer, note that it should be possible to trace all C atoms in a chain without lifting the pencil and without retracing the pencil.

The following examples show some hydrocarbons with the longest chain in red box. The number of C atoms in the longest chain is also displayed. To keep things simple, only C atoms are shown, though, in reality, there will be H atoms too.

Step 2:

Find the parent name of the hydrocarbon based on the number of C atoms in the longest chain, as given in the following table:-

There may more number of C atoms. But, in most of cases, the above table will suffice.

Will post further steps later.