1(3H)-isobenzofuranone, 3-hydroxy- 16859-59-9 2-formyl-benzoic acid 2-formyl-benzoic acid, lactol form 3-hydroxy-1(3H)-isobenzofuranone 3-hydroxy-2-benzofuran-1(3H)-one 3-hydroxy-3H-isobenzofuran-1-one InChI=1/C8H6O3/c9-7-5-3-1-2-4-6(5)8(10)11-7/h1-4,7,9 phthalaldehydic acid