InChI=1/C9H10/c1-2-8-4-3-7(1)9(8)5-6-9/h1-4,7-8H,5-6H spiro[bicyclo[2.2.1]hepta-2,5-diene-7,1'-cyclopropane] spiro[bicyclo[2.2.1]heptane-7,1'-cyclopropane]-2,5-diene