.alpha.-Cetone .alpha.-Ionone, isomethyl- .alpha.-Isomethylionone 127-51-5 3-Buten-2-one, 3-methyl-4-(2,6,6-trimethyl-2-cyclohexen-1-yl)- 4-(2,6,6-Trimethyl-2-cyclohexen-1-yl)-3-methyl-3-buten-2-one Cetone alpha Iso-.alpha.-methyl ionone Isomethyl-.alpha.-ionone Methyl-.alpha.-isoionone NSC66432