Give all the structural isomers `(` excloding stereoisomers and allenes `)` of diene with the molecular formula `C_(6)H_(10)`.

Explanation

`D.U.` IN `C_(6)H_(10)=((2n_(C)+2)-n_(H))/(2)=(14-10)/(2)=2^(0)`
`(` Two `(C=C)` bonds `).` Both the double bonds should be terminal so that it does not show geometrical isomers.
`I.` Hexa `-1,5-`diene
`II.` `3-`Methyl prenta `-1,4-`diene
`III.` `2-`Methyl penta `-1,4-`diene
`IV.` `2,3-`Dimethyl buta `-1,3-`diene
`V.` `2-`Ethyl buta `-1,3-`diene
If bond is internal, it must contain two same groups, so that it does not show geometrical isomers.
`VI.` `4-`Methyl penta `-1,3-` diene
Total number of isomers `=6`