2-Oxo-5-methylhex-3-ene 3-01-00-03005 (Beilstein Handbook Reference) 3-Hexen-2-one, 5-methyl- 5-METHYL-3-HEXEN-2-ONE 5-Methylhex-3-en-2-one 5166-53-0 AI3-22171 BRN 1720101 EINECS 225-950-5 FEMA No. 3409