A preparation method for optically active citronellal, which can obviously enhance the catalytic stability of an optically active transition metal catalyst for asymmetric hydrogenation of homogeneous catalysis and thereby achieve higher turnover numbers. In the preparation method for optically active citronellal, a substrate is subjected to an asymmetric hydrogenation reaction in the presence of the transition metal catalyst to generate the optically active citronellal, wherein the transition metal catalyst is obtained by reacting a transition metal compound with an optically active ligand containing two phosphorus atoms, and the raw material of the substrate is one of neral and geranial or a combination thereof to control the hydroxyl value to be less than or equal to 6 mgKOH/g and/or the iron content to be less than or equal to 50 ppm in the raw material of the substrate for the asymmetric hydrogenation reaction.

A preparation method for optically active citronellal, which can obviously enhance the catalytic stability of an optically active transition metal catalyst for asymmetric hydrogenation of homogeneous catalysis and thereby achieve higher turnover numbers. In the preparation method for optically active citronellal, a substrate is subjected to an asymmetric hydrogenation reaction in the presence of the transition metal catalyst to generate the optically active citronellal, wherein the transition metal catalyst is obtained by reacting a transition metal compound with an optically active ligand containing two phosphorus atoms, and the raw material of the substrate is one of neral and geranial or a combination thereof to control the hydroxyl value to be less than or equal to 6 mgKOH/g and/or the iron content to be less than or equal to 50 ppm in the raw material of the substrate for the asymmetric hydrogenation reaction.

The present invention relates to 2,4-diethylocta-2,6-dienal and a method of preparing same, to the use of 2,4-diethylocta-2,6-dienal as aroma chemical; to the use of 2,4-diethylocta-2,6-dienal for preparing an aroma chemical composition or for modifying the aroma character of an aroma chemical composition; to an aroma chemical composition containing 2,4-diethylocta-2,6-dienal; and to a method of preparing an aromatized composition or for modifying the aroma character of an aromatized composition.

The present invention relates to 2,4-diethylocta-2,6-dienal and a method of preparing same, to the use of 2,4-diethylocta-2,6-dienal as aroma chemical; to the use of 2,4-diethylocta-2,6-dienal for preparing an aroma chemical composition or for modifying the aroma character of an aroma chemical composition; to an aroma chemical composition containing 2,4-diethylocta-2,6-dienal; and to a method of preparing an aromatized composition or for modifying the aroma character of an aromatized composition.

The present disclosure provides a composition. In an embodiment, the composition includes 2-heptylundecanol; a member selected from the group consisting of 2-ethyhexanol and 2-propylheptanol; and a mixture of an alcohol (1) and an alcohol (2), alcohol (1) having the Structure (1) wherein R.sub.1 is selected from the group consisting of an ethyl group and a propyl group, R.sub.2 and R.sub.3 each independently is selected from the group consisting of hydrogen and an alkyl group, with the proviso that the total number of carbon atoms of R.sub.1 and R.sub.2 is 7, and alcohol (2) having the Structure (2) wherein R.sub.4 is selected from the group consisting of an n-propyl group, an isopropyl group, an n-butyl group, and an isobutyl group.

The present disclosure provides a composition. In an embodiment, the composition includes 2-heptylundecanol; a member selected from the group consisting of 2-ethyhexanol and 2-propylheptanol; and a mixture of an alcohol (1) and an alcohol (2), alcohol (1) having the Structure (1) wherein R.sub.1 is selected from the group consisting of an ethyl group and a propyl group, R.sub.2 and R.sub.3 each independently is selected from the group consisting of hydrogen and an alkyl group, with the proviso that the total number of carbon atoms of R.sub.1 and R.sub.2 is 7, and alcohol (2) having the Structure (2) wherein R.sub.4 is selected from the group consisting of an n-propyl group, an isopropyl group, an n-butyl group, and an isobutyl group.

A catalyst containing, as an essential component, molybdenum; bismuth; and cobalt, in which, with respect to a peak intensity at 2θ=25.3°±0.2° in an X-ray diffraction pattern obtained by using CuKα rays as an X-ray source, a changing rate (Q1) per 1000 hours of reaction time represented by the following formulae (1) to (4) is 16 or less.

Q1={(U1/F1−1)×100}/T×1000  (1)

F1=(peak intensity of catalyst before oxidation reaction at 2θ=25.3°±)0.2°/(peak intensity of catalyst before oxidation reaction at 2θ=26.5°±0.2°)×100  (2)

U1=(peak intensity of catalyst after oxidation reaction at 2θ=25.3°±0.2°)/(peak intensity of catalyst after oxidation reaction at 2θ=26.5°±0.2°)×100  (3)

T=time (hr) during which oxidation reaction is carried out  (4)

A catalyst containing, as an essential component, molybdenum; bismuth; and cobalt, in which, with respect to a peak intensity at 2θ=25.3°±0.2° in an X-ray diffraction pattern obtained by using CuKα rays as an X-ray source, a changing rate (Q1) per 1000 hours of reaction time represented by the following formulae (1) to (4) is 16 or less.

Q1={(U1/F1−1)×100}/T×1000  (1)

F1=(peak intensity of catalyst before oxidation reaction at 2θ=25.3°±)0.2°/(peak intensity of catalyst before oxidation reaction at 2θ=26.5°±0.2°)×100  (2)

U1=(peak intensity of catalyst after oxidation reaction at 2θ=25.3°±0.2°)/(peak intensity of catalyst after oxidation reaction at 2θ=26.5°±0.2°)×100  (3)

T=time (hr) during which oxidation reaction is carried out  (4)

Aldehydes of formula (I) (X represents an alkyl or alkenyl group having up to 9 carbon atoms) for use in taste modulation and/or flavor compositions are provided. Specifically, the compounds of the presently disclosed subject matter provide effective and unexpected taste modulating properties. The taste modulation and/or flavor compositions can be incorporated into various consumer end products in particular in combination with high intensity sweeteners. ##STR00001##

Aldehydes of formula (I) (X represents an alkyl or alkenyl group having up to 9 carbon atoms) for use in taste modulation and/or flavor compositions are provided. Specifically, the compounds of the presently disclosed subject matter provide effective and unexpected taste modulating properties. The taste modulation and/or flavor compositions can be incorporated into various consumer end products in particular in combination with high intensity sweeteners. ##STR00001##