What is the IUPAC convention for naming alkenes?
• Find and name the longest continuous carbon chain, label it as the base name and use the appropriate suffix: “-ene,” indicating an alkene or cycloalkene. • The base chain must include the carbon atoms involved in the double bond. • Number the longest chain from the end that is closest to the double bond. • If the double bond is in the center of the chain, begin numbering from an end that has a substituent closest to the end of the root chain. • Identify any double bonds using the lowest-numbered carbon, e.g. 2-pentene for a double between the 2nd and 3rd carbon. • If there is more than one double bond, use the same numbering approach, i.e. choose the lowest-numbered carbon to identify the location of the double bond. • Alkenes with multiple double bonds have special designations: e.g. dienes have 2 C=C bonds, trienes have 3 C=C bonds, etc. • Identify their locations by using the lowest-numbered carbons. For example, 2,3-pentadiene is the name for a five carbon diene with double bon
