2-((3,5-Bis(1,1-dimethylethyl)-4-hydroxyphenyl)methylene)butanoic acid 83677-21-8 Butanoic acid, 2-((3,5-bis(1,1-dimethylethyl)-4-hydroxyphenyl)methylene)- beta-Carboxy-beta-ethyl-3,5-di-tert-butyl-4-hydroxystyrene