Answer
The IUPAC name of the alkene is $2,5-dimethylcyclopenta-1,3-diene$
Work Step by Step
The compound has 5 carbon atoms in its longest carbon ring containing the double bond ($pent-$). It has 2 $methyl-$ substituent at positions 2 and 5, and 2 double bonds at positions 1 and 3. So, the IUPAC name of the alkene is $2,5-dimethylcyclopenta-1,3-diene$