IUPAC:4'-methylidene-1-(3-{4'-methylidene-2,5'-dioxo-1,2-dihydrospiro[indole-3,2'-oxolan]-1-yl}propyl)-1,2-dihydrospiro[indole-3,2'-oxolane]-2,5'-dione
IUPAC:4'-methylidene-1-(3-{4'-methylidene-2,5'-dioxo-1,2-dihydrospiro[indole-3,2'-oxolan]-1-yl}propyl)-1,2-dihydrospiro[indole-3,2'-oxolane]-2,5'-dione