Abstract: An economical process for producing (2- and/or 1-)cyclohexenyl methyl ketones which are intermediates for the synthesis of &agr;- or &bgr;-damascone. In the presence of a catalyst, a 3-cyclohexenyl methyl ketone represented by the following formula (1a): wherein, R1, R2 and R3 each independently represents a hydrogen atom or a methyl group and at least two of R1, R2 and R3 are methyl groups, is isomerized.

Abstract: Trans-2,2,6-trimethylcyclohexyl methyl ketone, including (1S,6R)-2,2,6-trimethylcyclohexyl methyl ketone represented by the formula (1a): and (1R,6S)-2,2,6-trimethylcyclohexyl methyl ketone represented by the formula (1b): are useful components in a perfume composition. A process for producing the same is also described. A unique eucalyptus, mint-like and white floral perfume material is provided using the ketone compounds disclosed in the present invention. The process of the present invention produces the optically active ketone compounds having optical purity up to at least 98.0 % e.e.

Abstract: A geometrical isomer composition excellent in odor and in chemical resistance, which is applicable to a base material containing a strongly alkaline chemical or a strongly acidic chemical, which can suppress the deterioration with time and the color change of the base material in the case that the material is exposed to light, and which also have highly palatable and unique fruity floral fragrance. The composition is produced by mixing 93 to 99% by weight of optically active ethyl trans-2,2,6-trimethylcyclohexylcarboxylate represented by Formula-1 or a mixture thereof and 7 to 1% by weight of optically active ethyl cis-2,2,6-trimethylcyclohexylcarboxylate represented by Formula-2 or a mixture thereof, respectively.

Abstract: A geometrical isomer composition excellent in odor and in chemical resistance, which is applicable to a base material containing a strongly alkaline chemical or a strongly acidic chemical, which can suppress the deterioration with time and the color change of the base material in the case that the material is exposed to light, and which also have highly tasteful and unique fruity floral fragrance. A geometrical isomer composition containing 93 to 99% by weight of optically active trans-1-(2,2,6-trimethylcyclohexyl)-2-buten-1-one represented by Formula-1 or a mixture thereof and 7 to 1% by weight of optically active cis-1-(2,2,6-trimethylcyclohexyl)-2-buten-1-one represented by Formula-2 or a mixture thereof is, respectively, used.

Abstract: Industrially advantageous processes for producing a 2-alkyl-2-cyclopentenone in high yields starting from a 2-(1-hydroxyalkyl)cyclopentanone or a 2-alkylidenecyclopentanone, which are obtainable from a cyclopentanone and a carbonyl compound.

Abstract: Trans-2,2,6-trimethylcyclohexyl methyl ketone, including (1S,6R)-2,2,6-trimethylcyclohexyl methyl ketone represented by the formula (1a): 1

Abstract: An economical process for producing (2- and/or 1-)cyclohexenyl methyl ketones which are intermediates for the synthesis of &agr;- or &bgr;-damascone.