Yes. But of course, there are chemicals in natural flavors too. Usually the same ones that are in artificial flavors.
A common artificial flavor is vanillin. Natural vanilla flavoring is a mixture of hundreds of different flavor molecules, but the most prevalent molecule in it is vanillin. Since vanillin can be synthesized much more cheaply than it can be extracted from vanilla beans, the synthetic form is much more widely available.
A more potent form of the molecule is ethyl vanillin. Both of these synthetic molecules are used to add flavor to foods such as chocolate, where the subtle differences between the natural and the synthetic molecules would be lost among all of the other strong flavors.
Many other artificial flavors have been synthesized. Most of them are esters, a compound made from an alcohol and an organic acid. As with vanillin, these molecules are the same ones found as the principal flavorings in natural flavors. For example, isoamyl acetate is the main molecule that gives bananas their flavor and aroma.
Octyl acetate is the main flavor component in oranges.