(3Z)-3-butylidene-4,5-dihydroxy-2-benzofuran-1(3H)-one 1(3H)-isobenzofuranone, 3-butylidene-4,5-dihydroxy-, (3Z)- InChI=1/C12H12O4/c1-2-3-4-9-10-7(12(15)16-9)5-6-8(13)11(10)14/h4-6,13-14H,2-3H2,1H3/b9-4