Syntheses of Eight Fragrant Terpenoids [Ionone Derivatives] via the Aldol Condensation of Citral and Eight Ketones

α-and β-ionones and seven ionone derivatives were synthesized from the base catalyzed condensation of citral (obtained from lemon grass Cymbopogon citratus essential oil) with eight different ketones. The pseudo-ionones obtained were acid cyclized to the respective ionone derivatives which were purified by vacuum liquid chromatography(VLC). The pure compound were analyzed and characterized by IR, UV, 1H-NMR, and MS. The 8 ketones are: 2-octanone, propanone, phenylethanone, 3-butenone, butanone, 3-pentanone, 4-methylpent-3-ene-2-one(mesityl oxide), and 2-methylcyclohexanone. Ionones and the derivatives synthesized have different but acceptable floral notes. They were obtained after purification in high yields (52 to 88%). The paper also reports the syntheses of Four Ionone derivatives which have not been reported earlier.