This invention provides a novel class of compounds and compositions and synthetic methods related to lactone antioxidant 3-arylbenzofuranones. The compounds may be useful to prevent yellowing and deterioration of organic materials preferably polymers, such as polyurethane foams as one example. The lactone antioxidants may be polymeric, and may also be liquid or paste in physical form at room temperature. Although it is not necessary for its stabilizing properties, the compositions may, in some species, bear one or more reactive primary OH groups on the polymer chains. The chains may also contain oligomeric oxyalkylene ether and aliphatic ester functional groups, in one embodiment of the invention.