Question

1(cyclohex-2,5-dienyl)-3(4-carboxyliccyclohex-2,5-diene)propane structure

Answer 1

This may be the structure, but again since you have not specified the position of the cyclohexa-1′,3′-dienyl through which the main ring is attached so I am taking it as 1′ position.

Note: There is a mistake in IUPAC naming for the compound: Since you have already used 1,3 for the original ring you have to use 1′,3′ for the side ring.