Alkenes are carbon chains that have double bonds. Alkynes are carbon chains that have triple bonds. The naming for these are very similar to that of alkanes.
The only differences are:
- Instead of using the suffix of “-ane”, use “-ene” if there are double bonds and “-yne” if there are triple bonds.
- An additional step is that you also have to specify the location number of the double or triple bond. Count the carbons and make sure that the named bond is at the lowest number possible. The numbering for bonds takes precedent over the numbering for attached groups. This means that, even if it makes the location numbers for an attached group to be larger than otherwise, you count carbons from the end of the chain that would make the bond location number smallest.