3,3,7,7-tetrakis(4-hydroxyphenyl)pyromellitide

7,7-bis(4-hydroxyphenyl)-3H-spiro[benzo[1,2-c:4,5-c']difuran-1,9'-xanthene]-3,5(7H)-dione

3',6'-dihydroxyspiro[oxolane-5,9'-xanthene]-2-one

1,1,2,2-四苯基乙烷