Answer
The IUPAC name of the alkene is $(3E,5E)-2,6−dimethylocta−1,3,5−triene$
Work Step by Step
The compound has 8 carbon atoms in its longest carbon chain containing the double bond ($oct−$). It has 2 $methyl−$ substituents at positions and 6, and 3 double bonds at positions 1,3 and 5. The bonds at position 3 and 5 are of $E$ stereo isomerism. So, the IUPAC name of the alkene is $(3E,5E)-2,6−dimethylocta−1,3,5−triene$
