Polyester polyols containing adducts formed from Diels-Alder and Ene reactions are disclosed. Processes for making the polyester polyols and uses of the polyester polyols as polyurethane coatings, adhesives, sealants, elastomers, and foams are also disclosed. In some embodiments, the polyester polyols contain biorenewable adducts based on maleic anhydride and farnesene and have particular application in making rigid and flexible polyurethane or polyisocyanurate foams.