## Organic Chemistry (8th Edition)

The structure is in the attached image. It's correct name is $trans-3-ethylhexa-1,4-diene$.
The vinyl group is a part of the main carbon chain (total 6 carbons), and the ethyl group is attached at position 3. There are 2 double bonds at positions 1 & 4. The compound is the $trans$ isomer. It's correct name is $trans-3-ethylhexa-1,4-diene$.