The listed ingredients are required by law to be listed because they are potential allergens/irritants. Unfortunately it tells you almost nothing if say, limonene is listed, as limonene is present in many essential oils.
I can't recall them all but I know that alpha isomethyl ionone, 3-cyclohexene carboxaldehyde (lyral), and butylphenyl methylpropional (lilial) are a few of the stand alone synthetics that have to be listed. Seeing those on a package does help somewhat, as you at least know that synthetic is present in the mix, but still, those chemicals are in tons of scents that smell nothing alike so it doesn't help much. :\