2-Hepten-4-one,5-methyl- , with CAS number of 81925-81-7, can be called 5-methyl-2-hepten-4-on ; filbertone ; 5-methyl-2-hepten-4-one ; 5-methyl-2-hepten-4-one 98% predominan ; 5-methyl-2-hepten-4-one,99% ; 5-methyl-2-hept-4-one .