Organic compounds -- part of the class 532-570 series – Organic compounds – Oxygen containing
Patent
1997-08-06
1998-12-08
Dees, Jose G.
Organic compounds -- part of the class 532-570 series
Organic compounds
Oxygen containing
568344, 568349, 568819, C07C 4500, C07C 3522
Patent
active
058472266
DESCRIPTION:
BRIEF SUMMARY
This application is a 371 of PCT/IB96/01371 filed Dec. 6, 1996.
TECHNICAL FIELD
The present invention relates to the field of organic synthesis and, more particularly, to a process for the preparation of nootkatone or nootkatol, or mixtures of these compounds, by oxidation of valencene, characterized in that the latter is exposed to an oxygen-containing atmosphere in an appropriate reaction medium and in the presence of a hydroperoxyde of an unsaturated fatty acid and in that, optionally, the nootkatone and/or the nootkatol is separated from the reaction mixture.
Nootkatone, or 4,4a,5,6,7,8-hexahydro-6-isopropenyl-4,4a-dimethyl-2(3H)-naphtalenone, nootkatol, or 2,3,4,4a,5,6,7,8-octahydro-6-isopropenyl-4,4a-dimethyl-2-naphtalenol, and valencene, or 1,2,3,5,6,7,8,8a-octahydro-7-isopropenyl-1,8a-dimethyl-naphthalene, the latter being used as starting material in the process of the invention, are compounds of natural origin, namely natural constituents of citrus oils, amongst which grapefruit, in which they are present in an optically active form.
Because of its excellent organoleptic qualities and in particular its typical grapefruit taste, nootkatone is a widely used ingredient in perfumery and the flavor industry. On the other hand, as a result of the legislation presently in force in most countries, relating to the use of nutrition additives, it is of capital importance to dispose of a process for the synthesis of this compound which is not only profitable and can be applied on an industrial scale, but which furthermore can supply this product in a quality which is satisfactory as regards established criteria as to its natural origin. Now, at present, such a quality can only be obtained by extraction of natural products containing nootkatone, in particular grapefruit, a method which is hardly economic.
PRIOR ART
A large number of syntheses has been described until now to obtain nootkatone by the oxidation of valencene. Amongst the oldest processes, one can cite the oxidation of valencene using tert-butyl chromate (see, for example, G. L. K. Hunter et al., in J. Food Sci. 1965, 30, 876) or tert-butyl peracetate (see C. W. Wilson et al., J. Agric. Food Chem. 1978, 26, 1430).
There are also other known chemical processes which use several reaction steps, starting from nootkatene (see, for example, Canadian patent n.degree. 901601), cyclohexene (see M. Pesaro et al., Chem. Comm. 1968, 19, 1152) or even cyclohexadiene (see A. J. Birch, J. Agr. Food Chem. 1974, 22, 162).
Finally, the bioconversion of valencene to nootkatone catalyzed by certain microorganisms (see R. S. Dhavlikar et al., Dragoco Rep. 1973, 12, 251), or starting from vegetable cell cultures (F. Drawert et al., Plant Cell Reports 1984, 3, 37) has also been studied, but these two methods can only provide nootkatone in yields which are too low to allow a commercial exploitation.
Thus, all these known processes turn out to be either not adapted to provide a product which fulfills the established criteria with respect to its natural character, or too complicated and too expensive, thus not adapted for an industrial scale exploitation.
DESCRIPTION OF THE INVENTION
The present invention brings precisely an advantageous solution to the problem of the synthesis of nootkatone.
The above-cited process of the invention is a one-step process, of very simple execution, which can provide nootkatone in very advantageous yields and in a quality which is in conformity with the requirements for a use in food products.
We have now discovered that it is henceforth possible to obtain this product by simple oxidation of valencene in the presence of a hydroperoxyde of an unsaturated fatty acid. This transformation is executed under an oxygen-containing atmosphere and in an appropriate reaction medium, i.e. favorable for the formation of the desired product in yields which are useful for a profitable and large-scale exploitation.
Moreover, as cited above, the process of the invention also makes it possible to obtain nootkatol. The latter is also a known compound
REFERENCES:
patent: 3887622 (1975-06-01), Boelens et al.
patent: 5030739 (1991-07-01), Foricher et al.
Willershausen et al. Metalkalytische Transformation von Valencen zu Nootkaton, Chemiker-Zeitung, 115, 1991, pp. 356-358.
Enzymatische Transformation von Valencen zu Nootkaton, Chemiker-Zeitung, 115, pp. 358-360, 1991.
Dean Christopher
Kuhn Jean-Charles
Muller Bernard
Schmidt Christian
Dees Jos,e G.
Firmenich SA
Pryor Alton
LandOfFree
Process for the preparation of nootkatone does not yet have a rating. At this time, there are no reviews or comments for this patent.
If you have personal experience with Process for the preparation of nootkatone, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Process for the preparation of nootkatone will most certainly appreciate the feedback.
Profile ID: LFUS-PAI-O-179356