What are IUPAC names for alkenes?
Alkenes and alkynes are hydrocarbons which respectively have carbon-carbon double bond and carbon-carbon triple bond functional groups.
IUPAC Rules for Alkene and Cycloalkene Nomenclature
The ene suffix indicates an alkene or cycloalkene.
The longest chain chosen for the root name must include both carbon atoms of the double bond .
- The root chain must be numbered from the end nearest a double bond carbon atom.
- The smaller of the two numbers designating the carbon atoms of the double bond is used as the double bond locator. If more than one double bond is present the compound is named as a diene, triene ,...
- In cycloalkenes the double bond carbons are assigned ring locations 1 and 2. Which of the two is No.1 may be determined by the nearest substituent rule.
Also very important, if there is more than one double bond, you choose the longest chain that contains the most double bonds. This may not be the longest chain of carbon atoms.