I heard that you could extract useful hydrocarbons, such as benzene, xylene and toluene from the destructive distillation of wood and charcoal.
These three compounds are useful but very cheap. Extracted train-wise from petrol, with very little transformation. I can't imagine wood pyrolysis on reasonable scale competing against that. Same for methanol and more compounds.
More generally, petrol and coal too are pyrolysis products of wood and similar substances. You find similar compounds in all of them. They are the compounds that form indistinctly from very rough and uncontrolled reactions. You get aromatics because of the H/C ratio and the stability of aromatic rings. Lighter alcohols, aldehydes and ketones at the beginning, polycyclic aromatics at the end.
In this context, I doubt that a major product of wood pyrolysis has a market value not spoiled by coal and petrol products. What you might try:
Find a minor compound that is not usually extracted from coal nor petrol. Since petrol is already well pyrolysed and coal even more, you might have better chances with the early pyrolysis products. Just a gut feeling. If you obtain for instance a solvent with pleasant odour, different from turpentine, it has more value than white spirit.
Or do more than a bare pyrolysis. Add some cheap compound (natural gas, alcohol, aldehyde, amine...) and check is something more useful comes out. Again, early products should be more differentiated than late ones.
Pyrolysis makes many moderate carcinogens, so you'll have to sort out the products.