3,6-dimethylspiro[4.4]nona-2,6-dien-1-one InChI=1/C11H14O/c1-8-6-10(12)11(7-8)5-3-4-9(11)2/h4,6H,3,5,7H2,1-2H spiro[4.4]nona-2,6-dien-1-one, 3,6-dimethyl-