ENRICHEMENT OF A DIASTEREOMER IN MAGNOLAN

Description

Field of invention

[0001] The invention relates to a distillation process for the production of a diastereomerically enriched fragrance mixture with a floral note comprising compounds of the general formula (A): as well as the diastereomerically enriched odorant mixture comprising compounds of general formula (A) obtainable from this process and its use as a odorant or for the production of a odorant preparation. Furthermore, the invention relates to the use of the diastereomerically enriched odorant mixture for imparting, modifying, or enhancing a floral odor note of a perfumed product or for the production of a perfumed product itself. Finally, the present invention relates to odorant preparations and perfumed products comprising the diastereomerically enriched odorant mixture. State of the art

[0002] 4,4a,5,9b-Tetrahydro-2,4-dimethylindeno[1,2-d][1,3]-dioxin is a popular fragrance ingredient with a primarily transparent, floral-green odor reminiscent of magnolias, geraniums, and grapefruit. The scent of this compound is often described as floral-green and very complex. Therefore, Magnolan (Symrise AG), as this fragrance ingredient is commercially known, is particularly used to create floral fragrance notes.

[0003] Furthermore, Magnolan (Symrise AG) is ideally suited for achieving specific floral notes in floral compositions and for achieving a special olfactory effect in fragrance compositions comprising dry and woody components.

[0004] German patent application DE 1 793 310 describes 2,6-dialkyl-4,5-indano-1,3-dioxane compounds, a process for producing these compounds, and their use in perfume manufacturing and as a perfume base. The application also discloses the production of 2,6-dimethyl-4,5-(1',2'-indeno)-1,3-dioxane, which has a rose-like odor similar to that of the Damask rose. The resulting product has two geometric isomers in a ratio of 1.8:1. In particular, this fragrance is intended for use as a supplement to or replacement for natural rose fragrances.

[0005] WO 2010 / 142815 A2 also discloses a fragrance mixture comprising magnolan. The olfactory properties of the fragrance are described as "white flower (especially white magnolia), floral (red flower, peony, geranium) and "indole-like".

[0006] Although the already established fragrance Magnolan (Symrise AG) has excellent olfactory properties in principle, it is often described that this fragrance also has a rather disturbing, technical and plastic-like odor note.

[0007] As described in DE 1 793 310, this is generally a product in which the diastereomeric isomers are present next to each other in almost equal distribution. Object of the invention

[0008] The invention is therefore primarily based on the general objective of optimizing commercially available fragrances and eliminating the disturbing odor notes, thereby ensuring an intense, more harmonious and "cleaner" floral odor impression, and providing a corresponding method for producing such an optimized fragrance.

[0009] A gentle process is of utmost importance in order to minimize any decomposition processes and potential side reactions as well as interactions between such decomposition products or side reaction products, which could further adversely affect the olfactory properties of the product itself or of the fragrance preparations and perfumed products containing the rich substance.

[0010] Although methods for producing magnolane are already known, these processes generally exhibit disadvantages in terms of isomer purity, particularly during upscaling, i.e., the production of the product on a large (industrial) scale: often, only low yields and selectivities, i.e., low purity, are observed. This consequently has a detrimental effect on the quality of the product, and especially on its odor properties, as previously explained.

[0011] Therefore, a further object of the present invention is to provide a simple and gentle manufacturing process which makes it possible to produce an optimized floral fragrance in a few steps and thus to provide the desired products cost-effectively and in high yield and purity.

[0012] Furthermore, one task concerns the provision of such a fragrance mixture, its use as a fragrance and for the manufacture of fragrance preparations and perfumed products, as well as fragrance preparations and perfumed products, encompassing this optimized fragrance mixture.

[0013] An additional object of the invention relates to the reduction or masking of an unpleasant odor and / or the enhancement of positive odor impressions, especially the enhancement of harmonious, intense and "clean" floral odor impressions.

[0014] Another task involves the gentle enrichment of isomers with positive odor properties and thus the targeted influencing of the fragrance without damaging or altering the fragrance substances.

[0015] Synthesis is conceivable, for example, starting from optically active starting materials, i.e., starting materials where the stereoselectivity of the starting compounds dictates the stereoisomerism of the products, or from isolated diastereomers, as described, for example, in Abate A. et al., "Enzyme-Mediated Preparation of Chiral 1,3-Dioxane Odorants", HELVETICA CHIMICA ACTA, Vol. 86, No. 3, March 2003, pages 592-606. However, such a process involves a multitude of elaborate and complex preceding synthesis and purification steps to provide the isolated enantiomers or diastereomers of the starting compounds. This also leads to a further objective of the present invention, namely, the provision of diastereomerically enriched magnolane products without the need to provide isomerism-directing intermediates as starting materials or intermediates.to provide a fast and efficient process with few process steps, which at the same time ensures high selectivity and also largely prevents decomposition reactions or side reactions that could otherwise have an adverse effect on the odor properties.

[0016] The problems posed are solved according to the invention by the subject matter of the independent claims. Further aspects and preferred embodiments of the present invention will become apparent from the wording of the dependent claims, the following description, and the exemplary embodiments. Summary of the invention

[0017] A first object of the present invention relates to a distillation process for producing a diastereomerically enriched fragrance mixture with a floral note comprising compounds of the general formula (A): the fragrance mixture comprises the following diastereomeric enantiomeric pairs: wherein the quantitative ratio of the enantiomeric pair (I) and the enantiomeric pair (II) to each other is at least 10:1 and the quantitative ratio of the enantiomeric pairs (I) and (III) to each other is at least 50:1, and wherein the process comprises the following distillation steps: (a) distillative separation of a crude product comprising compounds of general formula (A) in a first distillation step; (b) subsequent fine distillation of the crude product through one or more distillation steps concentrating the enantiomeric pair (I) in relation to the enantiomeric pairs (II) and (III), wherein the fine distillation comprises at least 15 separation stages.

[0018] It has been shown that odorant mixtures with lower amounts of isomer (III) exhibit a better odor impression of the magnolane odorant. Furthermore, the odorant mixtures should contain higher proportions of isomer (I) relative to isomer (II). This selective enrichment is surprising, as no selective enrichment methods for the enantiomeric pair (I) compared to the enantiomeric pairs (II) or (III) were previously known, nor are any expected. Such high enrichments are particularly surprising. Moreover, this enrichment was achieved using technically advantageous processes that are both cost-effective and efficient.

[0019] In a second object, the present invention comprises a diastereomerically enriched fragrance mixture comprising compounds of general formula (A), wherein the compounds of formula (A) comprise the diastereomeric enantiomeric pairs of formulas (I), (II) and (III), wherein the quantitative ratio of the enantiomeric pair (I) and the enantiomeric pair (II) to each other is at least 10:1, and the quantitative ratio of the enantiomeric pairs (I) and (III) to each other is at least 501 (referring to the entire fragrance mixture comprising compounds of general formula (A), i.e., compounds (I), (II) and (III)).

[0020] The third subject of the present invention is the use of the diastereomerically enriched fragrance mixture as a fragrance or for the production of a fragrance preparation.

[0021] In a fourth aspect, the present invention relates to a fragrance preparation containing a sensorially effective amount of the diastereomerically enriched fragrance mixture.

[0022] Another object of the present invention is the use of the diastereomerically enriched odorant mixture in a sensorially effective quantity for conveying, modifying or enhancing a floral odor note of a perfumed product or for the manufacture of a perfumed product as such.

[0023] Finally, in a further aspect, the present invention relates to a perfumed product comprising the diastereomerically enriched fragrance mixture or a fragrance preparation comprising therein.

[0024] Surprisingly, it was found within the scope of the present invention that diastereomerically enriched odorant mixtures can be obtained using the method described herein (preferably racemic) which exhibit a more natural and intense floral, rosy, warmer, transparent, and radiant geranium-scented odor profile. This profile is perceived as less technical than commercially available Magnolan and does not exhibit any plastic-like odor notes. Furthermore, the odor is perceived as less green, more intensely rosy, and less reminiscent of grapefruit compared to commercially available Magnolan.

[0025] Furthermore, the method described herein makes it possible to produce the (preferably racemic) diastereomerically enriched odorant mixture in very high yield and excellent purity in only a few synthesis and processing steps, which characterize the method described herein as a highly efficient, highly selective, and reliable, i.e., reproducible, process. The resulting odorants with an intensely floral note enable the production of improved odorant compositions with distinctive olfactory notes and aspects, free from the disturbing technical and plastic-like odor components. Accordingly, the odor of the substances, preparations, and products described herein is perceived as more floral and "cleaner."

[0026] These and other aspects, as well as further features and advantages of the present invention, will become apparent to the person skilled in the art upon study of the following detailed description and the claims. Any feature from one aspect of the invention can be used or substituted in another aspect of the invention. The examples included in this application describe the invention without limiting it.

[0027] Advantageous further developments and variants of the invention are specified in the dependent claims.

[0028] All percentages are weighted percent unless otherwise stated. Numerical examples given in the form "from x to y" include the stated values. If multiple preferred numerical ranges are given in this format, all ranges resulting from combining the different endpoints are also included. Figures

[0029] Figure 1a and 1b show the 1< H-NMR spectrum (600 MHz, Chloroform-d) of a first diastereomerically enriched fragrance mixture according to the invention. Figure 2 The 13< C-NMR spectrum (151 MHz, CDCl 3 ) shows a first diastereomerically enriched fragrance mixture according to the invention. Figure 3 The gas chromatographic analysis of a second diastereomerically enriched odorant mixture according to the invention is shown. Detailed description of the invention

[0030] In a first aspect, the present invention relates to a distillation process for the production of a (preferably racemic) diastereomerically enriched fragrance mixture with a floral note comprising compounds of the general formula (A): the fragrance mixture comprises the following diastereomeric enantiomeric pairs: wherein the quantitative ratio of the enantiomeric pair (I) and the enantiomeric pair (II) to each other is at least 10:1 and the quantitative ratio of the enantiomeric pairs (I) and (III) to each other is at least 50:1, and wherein the process comprises the following distillation steps: (a) distillative separation of a crude product comprising compounds of general formula (A) in a first distillation step; (b) subsequent fine distillation of the crude product through one or more distillation steps concentrating the enantiomeric pair (I), in particular in relation to the enantiomeric pairs (II) and (III), wherein the fine distillation comprises at least 15 separation stages.

[0031] Those skilled in the art are aware that the compound of general formula (A) is a chiral compound. Furthermore, they are aware that these enantiomeric pairs are diastereomers of each other, while the enantiomers of the enantiomeric pair, as the name already suggests, are enantiomers of each other, i.e., they are mirror images of each other. An enrichment of a diastereomer therefore means the production of a quantitative excess of one of these enantiomeric pairs, here enantiomeric pair (I), relative to the other existing enantiomeric pairs of the fragrance mixture, here enantiomeric pairs (II) and (III) of general formula (A).

[0032] In this context, the term "diastereomerically enriched" therefore refers to the proportion of a diastereomer, i.e., a preferred enantiomeric pair, in the mixture with the other possible diastereomers of the compound under consideration, i.e., of the general formula (A). The term "diastereomerically enriched" means that the fragrance mixtures obtainable by the process described herein have a significantly higher content of enantiomeric pair (I) relative to the diastereomeric enantiomeric pairs (II) and (III) than the magnolane products obtainable by conventional methods and commercially distributed. Consequently, within the scope of the invention, the term "diastereomerically enriched" describes the presence of a diastereomer, i.e., enantiomeric pair (preferably enantiomeric pair (I)), as defined above, with a proportion in the mixture with the other possible diastereomeric isomers in the range of > 50 wt.% and 100 wt.%.In particular, the term "diastereomerically enriched fragrance mixture" shall be understood to mean a mixture which contains at least 80 wt.% to 99.9 wt.%, preferably 90 wt.% to 99.8 wt.% and particularly preferably 95 wt.% to 99.5 wt.% of the enantiomeric pair (I) comprising the enantiomers of formulas (1a) and (1b), in addition to a total of up to 20 wt.%, preferably up to 10 wt.%, and particularly preferably 5 wt.% to 0.5 wt.% of the further diastereomeric enantiomeric pairs (II) and / or (III).

[0033] In the context of the present invention, the terms "compounds of formula (I)" or "enantiomeric pair of formula (I)" or "enantiomeric pair (I)", "compound (I)" and "isomer (I)" are understood to mean both the individual enantiomeric compounds of formula (I) and consequently the enantiomers (1a) and (Ib) as well as all mixtures of these enantiomers in any mixing ratio. That is to say, statements in the following description concerning "enantiomeric pair (I)" apply both to a single compound of formula (I) and thus the enantiomers (1a) and (Ib) as well as to mixtures consisting of or comprising the enantiomers (1a) and (Ib) in any mixing ratio. The same applies to the terms "enantiomeric pair (II)" and "enantiomeric pair (III)".

[0034] However, the enantiomers (1a) and (1b), (IIa) and (IIb), and (IIIa) and (IIIb) are preferably each contained in such a way that the enantiomeric pairs (I), (II), and (III) are present in a racemic mixture of the respective enantiomers (1a) and (Ib), (IIa) and (IIb), and (IIIa) and (IIIb), respectively. Consequently, a further preferred embodiment relates to the provision of a racemically diastereomerically enriched fragrance mixture, wherein the enantiomeric pairs (I), (II), and (III) are each present in racemic form, but especially the enantiomeric pair (I). Such racemic compounds, and consequently racemically diastereomerically enriched fragrance mixtures, exhibit a particularly balanced and harmonious odor.

[0035] The compounds of general formula (A) bear the following designations: Enantiomer pair (I): Enantiomer (la): (2S,4S,4aS,9bR)-2,4-dimethyl-4,4a,5,9b-tetrahydroindeno[1,2-d][1,3]dioxine Enantiomer (Ib): (2R,4R,4aR,9bS)-2,4-dimethyl-4,4a,5,9b-tetrahydroindeno[1,2-d][1,3]dioxine Enantiomer pair (II): Enantiomer (IIa): (2R,4R,4aS,9bR)-2,4-dimethyl-4,4a,5,9b-tetrahydroindeno[1,2-d][1,3]dioxine Enantiomer (IIb): (2S,4S,4aR,9bS)-2,4-dimethyl-4,4a,5,9b-tetrahydroindeno[1,2-d][1,3]dioxine Enantiomer pair (III): Enantiomer (IIIa): (2R,4S,4aS,9bR)-2,4-dimethyl-4,4a,5,9b-tetrahydroindeno[1,2-d][1,3]dioxine Enantiomer (IIIb): (2S,4R,4aR,9bS)-2,4-dimethyl-4,4a,5,9b-tetrahydroindeno[1,2-d][1,3]dioxine

[0036] The resulting (preferably racemic) diastereomerically enriched fragrance mixture, comprising the compounds of general formula (I), includes the enantiomeric pair (I) relative to the enantiomeric pair (II) in the mixture in a ratio of at least 10:1. Preferably, the ratio of the enantiomeric pair (I) and the enantiomeric pair (II) in the mixture to each other is at least 15:1, more preferably at least 20:1, and even more preferably at least 50:1. A further preferred ratio of these diastereomeric enantiomeric pairs to each other is at least 100:1.

[0037] As described in DE 1 793 310, 2,6-dialkyl-4,5-indano-1,3-dioxane comprises two main geometric isomers, which exist in a ratio of only 1.8 : 1. The Prins reaction, in itself, is generally considered a very unselective method, which usually leads to the formation of the enantiomeric pairs in nearly equal amounts.

[0038] Within the scope of the present invention, it has surprisingly been found that one of these isomers, which normally occur in a nearly statistical distribution in conventional magnolane synthesis, is perfumerically preferable. The method described herein makes it possible to significantly enrich the preferred isomer, isomer (I), in the resulting fragrance mixture compared to the second main isomer, thereby positively influencing the olfactory properties of the resulting fragrance.

[0039] Thus, using the present method, it was possible to enrich the proportion of the preferred isomer in the fragrance mixture to over 95 wt% relative to the other isomers present, thereby significantly emphasizing the positive odor components of the fragrance mixture. Furthermore, it was surprisingly found that the compounds of the enantiomeric pair (I) are particularly responsible for the positive odor characteristics of the fragrance mixture, and that the isomer distribution described above enables the production of a particularly intensely floral, "clean," and balanced odor, while the method described herein is itself highly selective, efficient, and gentle.

[0040] A further embodiment of the method described herein relates to the provision of a diastereomerically enriched fragrance mixture, as described above, wherein the proportion of enantiomeric pair (I) in the fragrance mixture is at least 95 wt.%, and more preferably at least 97.5 wt.%, and even more preferably at least 98.5 wt.%, based on the sum of the enantiomeric pairs (I), (II), and (III). Such a fragrance mixture exhibits an exceptionally pleasant and intensely floral odor profile, in which no technical or otherwise negatively perceived odor notes are discernible, i.e., a "clean," intensely floral odor profile.

[0041] Accordingly, a further embodiment of the present manufacturing process relates to the provision of a diastereomerically enriched fragrance mixture comprising at least 95 wt.% of the (preferably racemic) enantiomeric pair (I), preferably 97.5 wt.%, and more preferably at least 98.5 wt.% based on the sum of the enantiomeric pairs (I), (II) and (III).

[0042] Such pure or highly enriched diastereomerically enriched odorant mixtures of the magnolane type are not known to date. Furthermore, it should be emphasized that such an odorant mixture was found to have a particularly balanced and especially natural warm and floral scent. It should also be emphasized that the process described herein is a highly selective and, at the same time, particularly gentle method.

[0043] Furthermore, it was surprisingly found that racemic enantiomeric pairs, especially those of formula (I), contribute significantly to a balanced, natural, floral, and intense odor profile. It was observed that diastereomerically enriched fragrance mixtures, as described herein, comprising the compounds of general formula (A) and, in particular, higher proportions of the racemic enantiomeric pair (I) compared to enantiomeric pairs (II) and / or (III), contribute to this exceptional odor profile. The resulting product was found to have a positive and optimized, natural, intensely floral, rosy, transparent, somewhat warmer, radiant, and geranium-like odor, and exhibits no technical or plastic-like nuances.In particular, the balanced, intense, exceptionally natural and "clean" floral odor nuances characterize the present fragrance mixture, which can be attributed to the diastereomeric enrichment with the preferably racemic enantiomeric pair (I) in the fragrance mixture of the first aspect and justify the suitability of the present fragrance mixture as a fragrance or fragrance base in a variety of complex fragrance preparations and perfumed products.

[0044] Furthermore, the resulting fragrance mixture, comprising the compounds of general formula (A), preferably includes the enantiomeric pairs (I) and (III) in a ratio of at least 50 : 1. More preferably, the ratio of the enantiomeric pairs (I) and (III) to each other is at least 100 : 1; even more preferably at least 1000 : 1; and most preferably, the corresponding ratio is at least 1360 : 1.

[0045] Thus, it was simultaneously possible to significantly minimize the odorant component, which was primarily responsible for the technical and plastic-like odor impression, and consequently to optimize the odorant mixture accordingly.

[0046] Accordingly, the present fragrance mixture preferably has a significantly higher proportion of the enantiomers (1a) and (1b) of the enantiomeric pair (1) relative to the other diastereomers in the fragrance mixture, i.e. the enantiomers (IIa) and (IIb) as well as (IIIa) and (IIIb) of the enantiomeric pairs (II) and (III).

[0047] Within the scope of the present invention, it was surprisingly found that, by means of the method described herein, diastereomerically enriched odorant mixtures can be obtained on enantiomeric pair (I) (preferably racemic), which exhibit an intense and naturally floral, rosy, generally somewhat warmer, transparent and radiant, geranium-scented odor profile and are perceived as less technical than commercially available magnolan and do not exhibit any plastic-like odor notes (and are thus perceived as "cleaner"). Consequently, the odor is more intense, natural, balanced, floral and "cleaner" than commercially available magnolan.

[0048] The process steps (a) and (b) of the distillative process for the production of a (preferably racemic) diastereomerically enriched fragrance mixture are explained in more detail below.

[0049] A first step (a) of the distillative process described herein involves the distillative separation of a crude product comprising compounds of the general formula (A). The product subjected to this first distillation step is a crude magnolane product, preferably obtained from the synthesis starting from indene and paraldehyde. The preparation of such a product is described below. In general, however, it is a magnolane product that has not undergone any additional purification step and is present directly in the reaction mixture following the reaction of the reactants.

[0050] The primary purpose of this first distillation step is coarse distillation, removing any residual solvents, catalyst residues, and unreacted starting materials from the fragrance mixture, which is essentially not yet diastereomerically enriched and comprises the compounds of formula (A) or the enantiomeric pairs (I), (II), and (III). If necessary, this process step is also carried out under reduced pressure.

[0051] Based on this first distillation step of the process, it is therefore possible to initially provide the odorant mixture in the form of a crude product by separating a Magnolan crude product of sufficient chemical purity, and to avoid chemical interactions with other substances contained in the crude product that could negatively affect the overall olfactory impression of the final diastereomerically enriched odorant mixture.

[0052] The crude product comprising compounds of general formula (A) has, for example, a chemical purity of at least 80%, preferably at least 90%, following coarse distillation.

[0053] Following this first distillation step, the process described herein for the production of a diastereomerically enriched fragrance mixture comprises a further distillation step, the fine distillation of the crude product comprising compounds of the general formula (A). This fine distillation is carried out via one or more distillation steps concentrating the enantiomeric pair (I), wherein the fine distillation comprises at least 15 separation stages. Preferably, however, the fine distillation comprises at least 18 separation stages and most preferably at least 20 separation stages.

[0054] Magnolane of formula (A) obtainable by ordinary synthesis usually has a composition in which the isomers (I) and (II) are distributed almost statistically to each other, but at most in a ratio of 2 : 1.

[0055] The distillation process to be carried out according to steps (a) and (b) according to the invention therefore also enables the production of diastereomerically enriched fragrance mixtures by targeted fine distillation from a substantially non-diastereomerically enriched starting compound, which basically has neither a significant enantiomeric nor a significant diastereomeric excess of one or more of the geometric isomers contained therein.

[0056] Preferably, the foreshots from the coarse distillation are subjected to the subsequent fine distillation. This allows for even higher (diastereomeric) purities and yields.

[0057] Furthermore, the process described herein is ideally suited for the large-scale production of the fragrance mixture, thus enabling the complete fulfillment of the perfume industry's needs. Of particular importance is the consistent product quality from batch to batch, which can be guaranteed with this process. The process exhibits exceptionally high selectivity, requires only a few steps, and is particularly gentle, effectively preventing any decomposition or side reactions. Consequently, the process described herein is a highly efficient method.

[0058] In particular, enrichments of the enantiomeric pair (I) with a proportion of over 95 wt% based on the sum of the enantiomeric pairs (I), (II) and (III) in the resulting fragrance mixture are therefore possible.

[0059] This enrichment is surprising, as no selective enrichments of the enantiomeric pair (I) compared to the enantiomeric pairs (II) or (III) were previously known or expected.

[0060] In a further preferred embodiment, the present invention relates to a process for producing a diastereomerically enriched fragrance mixture as described above, which further comprises, prior to the distillation steps (coarse and fine distillation): the provision of paraldehyde of general formula (IV) or acetaldehyde, as well as its reaction with indene of the general formula (V) under acidic catalysis in the solvent, wherein the reaction of paraldehyde or acetaldehyde with indene takes place at temperatures below 10 °C; and recovery of the crude product comprising compounds of general formula (A).

[0061] Consequently, this preferred embodiment describes the synthesis of the magnolane crude product, which can be subjected to the distillative process of the first aspect and preferably is subjected to the distillative process of the first aspect.

[0062] In a further embodiment of this synthesis, the reactions of the compounds of general formulas (IV) and (V) take place under acidic catalysis, preferably in the presence of dilute sulfuric acid in toluene.

[0063] Essentially, the mechanism of the synthesis corresponds to the basic features of the so-called classical Prins reaction, i.e., an acid-catalyzed carbonyl-ene reaction, a form of cycloaddition which describes the electrophilic addition of an aldehyde or ketone to an alkene or alkyne.

[0064] Consequently, the process described herein continues to concern the provision of the crude product (2,4,4a,9b)-2,4-dimethyl-(4,4a,5,9b)-tetrahydronideno[1,2d][1,3]dioxin by classical Prins reaction under optimized process conditions.

[0065] The reaction of the compounds of formulas (IV) and (V) of the process according to the first aspect of the invention to form the crude product of general formula (A) is preferably carried out over a period of about 5 hours. Furthermore, it is preferred that the acidic catalysis be carried out by reaction in an emulsion of dilute sulfuric acid and toluene.

[0066] Using this method, very high chemical purities and yields could already be achieved with respect to the crude product (which is not yet diastereomerically enriched).

[0067] Preferably, no other substances, such as antioxidants, iodine, enzymes or other salts, are involved in the reaction.

[0068] This reaction step of the reactants exhibits no selectivity whatsoever with respect to the individual enantiomeric or diastereomeric isomers of the compounds of general formula (A). Consequently, the crude product of formula (A) typically exists as a mixture of a largely statistically distributed amount of the individual geometric isomers; that is, the enantiomeric pairs (I), (II), and (III) are present in the crude product of general formula (A) in an almost statistically distributed manner.

[0069] The enantiomers and (preferably racemic) diastereomers mainly formed in this process can be described by the formulas (1a), (1b), (IIa), (IIb), (IIIa) and (IIIb) or (I), (II) and (III).

[0070] It was found that the diastereomeric enantiomeric pairs (I), (II), and (III) exhibit distinct odor profiles. The odor of enantiomeric pair (I) can be described as floral, rosy, transparent, radiant, and geranium-like, while enantiomeric pair (II) evokes a floral, green, somewhat technical, grapefruit-like, and weaker odor compared to enantiomeric pair (I). Furthermore, it was surprisingly found that enantiomeric pair (III) exhibits a floral, technical, unclean, and plastic-like odor profile. An odor description of this enantiomeric pair (III) has now been identified and described for the first time within the scope of the present invention.

[0071] Furthermore, it has been shown that isomer (I) is the most odor-wise valuable isomer of the three identified diastereomeric isomers, so that the diastereomer-selective enrichment of the fragrance mixture with the geometric isomers of the preferably racemic enantiomeric pair (I) is particularly desirable and there is a need for an efficient and selective process to enrich in particular the isomers of the enantiomeric pair (I) in the fragrance mixture to be produced.

[0072] Simultaneously, a reduction in the proportion of enantiomeric pair (III) is therefore preferred with regard to the odor characteristics perceived as negative. It is of particular interest that the ratio of enantiomeric pairs (I) and (III) to each other is at least 50:1.

[0073] At the same time, or independently of this, it is also desirable that the quantitative ratio of the enantiomeric pair (I) and the enantiomeric pair (II) to each other is at least 10 : 1.

[0074] It was surprisingly found that when the diastereomeric enantiomeric pairs (I), (II) and (III) are present in these ratios to each other, particularly intense radiant, warmer, more natural, and transparent floral or flowery odor profiles can be achieved for the corresponding fragrance mixtures, which exhibit a special balance.

[0075] Standard methods for isolating an enantiomer or diastereomer, or an enantiomeric pair, are generally associated with numerous intermediate steps, such as the targeted provision of specific starting materials in predetermined stereoisomers or the enzymatic control of the geometry. Furthermore, such methods are usually neither gentle nor particularly efficient or selective overall.

[0076] However, the method described herein for providing a (preferably racemic) diastereomerically enriched fragrance mixture comprising the compounds of general formula (A) and the enantiomeric pairs (I), (II), and (III) has succeeded in enriching the proportion of enantiomeric pair (I) relative to its diastereomers to such an extent that the resulting product emits a positive and optimized, natural, intensely floral, rosy, transparent, somewhat warmer, radiant, and geranium-like odor. In particular, the high intensity, purity, and naturalness of the odor characterize the present fragrance mixture as an excellent fragrance / fragrance mixture or as an excellent fragrance base for further use in the production of naturally and intensely floral-smelling fragrance preparations and perfumed products.In conjunction with the reduced technical, unclean, and plastic-like nuances, this results in an excellent fragrance blend with an exceptional, balanced, intense, and "clean" floral scent, which can be incorporated superbly into complex fragrance creations. These olfactory nuances can be achieved with fragrance blends that contain the enantiomeric pairs (I), (II), and (III) in the proportions according to the invention. A certain proportion of enantiomeric pair (II) in the fragrance blend can also contribute to a more intensely floral, greener, and thus more natural floral component. Particularly natural nuances are of special interest in the perfume industry.Thus, the fragrance mixture described here can provide the perfume industry with a fragrance component which, due to its particularly intense floral, balanced and surprisingly "clean" odor profile, is especially well suited as a natural floral fragrance component in various preparations and products.

[0077] Furthermore, a highly selective, simple and gentle manufacturing process has now been developed, which makes it possible to produce an optimized, intensely floral fragrance in just a few steps, thus providing it cost-effectively, extremely pure and in high yield.

[0078] At the same time, the method described herein enables the efficient and highly selective diastereomeric enrichment of the enantiomeric pair (I) starting from the synthesis of the crude product by means of a classical Prins reaction in high yields and in high product purity.

[0079] Furthermore, it was found that the method described herein can be used to produce fragrance mixtures that exhibit a floral, rosy, transparent, radiant, and geranium-like scent. The diastereomerically enriched fragrance mixtures produced in this way show no technical or plastic-like odor notes. The grapefruit scent also recedes significantly into the background, so that the resulting fragrance mixture essentially has a much brighter, more intense, and more natural floral scent impression than commercially available Magnolan products.

[0080] In another preferred alternative, the process described herein for the production of a diastereomerically enriched fragrance mixture according to the first aspect is carried out in such a way that the fine distillation of the distillative process takes place in a continuous process.

[0081] This continuous process reduces the number of intermediate steps, such as refilling or cooling and heating the apparatus, and is therefore more economical compared to batch processes, ensuring consistent product quality. Accordingly, this method is also suitable for the industrial-scale production of the described fragrance mixture, enabling the high-quality production of the diastereomer-enriched fragrance mixture in quantities exceeding 180 kg with excellent fragrance properties and outstanding purity.

[0082] In a further preferred embodiment, the fine distillation step in the distillative process according to the first aspect of the invention for the production of a diastereomerically enriched fragrance mixture is carried out at a reflux ratio of at least 5:1. Preferably, said reflux ratio is at least 7:1 and most preferably at least 10:1 in order to achieve particularly high proportions of enantiomeric pair (I) relative to enantiomeric pairs (II) and (III) and to minimize the odor components described as negative and technical or plastic-like, while the intensely floral and positive odor impressions come to the fore.

[0083] Within the scope of the present invention, it was surprisingly found that such a reflux ratio in combination with the parameters described above leads to a particularly efficient and strong diastereomeric enrichment of the enantiomeric pair (I) in the fragrance mixture described herein.

[0084] Furthermore, in the inventive process according to the first aspect, the fine distillation of the distillative process is preferably carried out at temperatures between 120 °C and 150 °C, preferably the head temperature is between 125 °C and 145 °C, even more preferably between 135 °C and 140 °C.

[0085] This enables efficient and highly selective enrichment of the preferred diastereomer, i.e., the enantiomeric pair (I), and ensures the reproducibility of the desired odor profile.

[0086] In a further preferred embodiment, the fine distillation of the distillative process described herein for the production of a diastereomerically enriched fragrance mixture is carried out at a reduced pressure of about 1 mbar to 100 mbar, preferably at a reduced pressure of about 1 mbar to 50 mbar, particularly preferably at a reduced pressure of about 1 mbar to 10 mbar and even more preferably at a reduced pressure of 10 mbar.

[0087] A process designed in this way enables the particularly efficient and gentle enrichment of the enantiomeric pair (I) as described herein. Particularly gentle enrichment is of great importance because it reduces unwanted decomposition. In the present invention, gentler enrichment thus means that both the thermal and pressure-related stresses during diastereomer enrichment are low, and the resulting diastereomerically enriched fragrance mixture does not suffer any negative thermal or pressure-related damage that could manifest itself in decomposition or a change in product properties such as color, odor, stability, etc., through the formation of decomposition products and byproducts.Such decomposition and by-products could interact adversely with the fragrance / fragrance mixture and thus reduce the overall product quality by, for example, causing unpleasant off-odors that distort or adversely affect the characteristic odor impression of the fragrance or fragrance mixture, or even adversely affect the stability of the fragrances and fragrance mixtures or the preparations and products containing the fragrances and fragrance mixtures.

[0088] Furthermore, the present invention relates to a method for producing a diastereomerically enriched fragrance mixture according to the first aspect, wherein the first coarse distillation step (a) describes a thin-film distillation.

[0089] The process according to the invention is therefore particularly suitable for the efficient production of highly diastereomerically enriched and pure fragrances or perfume mixtures in high yields through the combination of gentle and selective production under mild conditions, resulting in an optimized, particularly intense, balanced, and natural floral odor. Temperature-sensitive substances, such as many fragrances and / or flavorings, may generally only be heated to high temperatures for short periods to counteract unwanted thermal decomposition processes. Classical distillation processes typically lead to prolonged thermal stress on the component being distilled, which can negatively affect both the yield and the quality of the products obtained. Efficient distillation processes with high selectivity, i.e.,High separation efficiency and simultaneously short residence times are therefore particularly preferred in the enrichment process. Since the thin-film evaporator in the present invention is preferably operated under vacuum, the process described herein allows the use of lower temperatures and is therefore suitable for the particularly gentle separation of the crude product as described herein. Thus, the process according to the invention is characterized overall as a very gentle process that reduces unwanted thermal and pressure-induced decomposition and with which the crude product can be efficiently and gently isolated with very high purities and yields, i.e., with excellent product quality.

[0090] Furthermore, another preferred embodiment of the process described herein for the production of a diastereomerically enriched fragrance mixture of the first aspect relates to a thin-film distillation comprising two stages: Separation of the solvent at a reduced pressure of about 1 mbar to 400 mbar, preferably at a reduced pressure of about 100 mbar to 300 mbar, particularly preferably at a reduced pressure of about 150 mbar to 250 mbar and even more preferably at a reduced pressure of about 200 mbar; and extraction of the crude product comprising compounds of general formula (A) at a reduced pressure of about 0 mbar to 100 mbar, preferably at a reduced pressure of about 0 mbar to 10 mbar, particularly preferably at a reduced pressure of about 0 mbar to 5 mbar; even more preferably at a reduced pressure of about 1 mbar.

[0091] Furthermore, in a particularly preferred embodiment of the process, the first stage of the thin-film distillation is carried out at a jacket temperature of between 120 °C and 200 °C, preferably, however, at temperatures between 150 °C and 180 °C, even more preferably at temperatures between 160 °C and 175 °C and particularly preferably at a temperature of about 165 °C, and the second stage of the thin-film distillation is carried out at a jacket temperature of between 150 °C and 250 °C, preferably, however, at temperatures between 180 °C and 210 °C, even more preferably at temperatures between 185 °C and 200 °C and particularly preferably at a temperature of about 190 °C.

[0092] This allows for an even gentler and more efficient extraction of the Magnolan crude product in terms of purity and yield.

[0093] In a second subject matter, the present invention comprises a (preferably racemic) diastereomerically enriched fragrance mixture comprising compounds of the general formula (A): the compounds of formula (A) comprise the following diastereomeric enantiomeric pairs of formulas (I), (II) and (III): wherein the quantitative ratio of the enantiomeric pair (I) and the enantiomeric pair (II) to each other is at least 10 : 1 and the quantitative ratio of the enantiomeric pairs (I) and (III) to each other is at least 50 : 1.

[0094] The (preferably racemic) diastereomerically enriched fragrance mixture of the second aspect, comprising the compounds of general formula (A), includes the enantiomeric pair (I) relative to the enantiomeric pair (II) in the mixture in a ratio of at least 10:1. Preferably, the ratio of the enantiomeric pair (I) and the enantiomeric pair (II) in the mixture to each other is at least 15:1, more preferably at least 20:1, and even more preferably at least 50:1. A further preferred ratio of these diastereomeric enantiomeric pairs to each other is at least 100:1.

[0095] Furthermore, the (preferably racemic) diastereomerically enriched fragrance mixture of the second aspect of the present invention comprises the compounds of general formula (A), the enantiomeric pairs (I) and (III) preferably in a ratio of at least 50:1. More preferably, the ratio of the enantiomeric pairs (I) and (III) to each other is at least 100:1; still more preferably at least 1000:1; and most preferably at least 1360:1.

[0096] The diastereomer-enriched fragrance mixture, which can be produced according to the process of the first aspect, has an intense floral, natural, rosy, transparent and radiant, geranium-scented odor, which is perceived as less technical than commercially available Magnolan and does not show any plastic-like odor notes, i.e. it is "cleaner".

[0097] Accordingly, diastereomerically enriched fragrance mixtures of general formula (A) are advantageous within the meaning of the present invention, having a higher proportion of enantiomeric pair (I) relative to enantiomeric pairs (II) and / or (III), particularly preferably in a ratio of enantiomeric pair (I) to enantiomeric pair (II) of at least 10:1 and a ratio of enantiomeric pair (I) to enantiomeric pair (III) of at least 50:1 in the fragrance mixture. Such fragrance mixtures exhibit enhanced floral, natural, "clean," rosy, transparent, and radiant geranium-scented odor profiles. The quantitative ratios as defined above are further preferred.

[0098] In a further preferred embodiment, the diastereomerically enriched fragrance mixture preferably contains the enantiomeric pair (I) in the rich mixture at a proportion of over 95 wt% (compared to all enantiomeric pairs of the fragrance mixture), which results in the positive odor components of the fragrance mixture being clearly emphasized. Such a fragrance mixture also exhibits an extremely pleasant and intensely floral and natural odor profile, in which no technical or otherwise negatively perceived odor notes are discernible.

[0099] A further embodiment of the present diastereomerically enriched fragrance mixture therefore relates to a fragrance mixture comprising at least 95 wt.% (compared to all enantiomeric pairs) of the (preferably racemic) enantiomeric pair (I). Preferably, however, the proportion of enantiomeric pair (I) is at least 97.5 wt.% and even more preferably at least 98.5 wt.% based on the sum of the enantiomeric pairs (I), (II) and (III) of the fragrance mixture according to the invention, so that particularly intense floral, "clean" and natural odor impressions can be achieved.

[0100] Furthermore, the diastereomerically enriched fragrance mixture exhibits high purity and can be provided in very high yield.

[0101] InIn a further preferred embodiment, the present invention relates accordingly to the diastereomerically enriched fragrance mixture of the second aspect, wherein the fragrance mixture comprises a total chemical purity of at least 96.5 wt.% of the enantiomeric pairs (I), (II) and (III), preferably at least 98.5 wt.%, most preferably at least 99.0 wt.%.

[0102] Such fragrance mixtures exhibit excellent secondary properties, such as high stability.

[0103] InIn a further optional embodiment, the remainder of the diastereomerically enriched odorant mixture represents further impurities, wherein the odorant mixture according to the invention contains, however, less than 3.0 wt.%, preferably less than 2.0 wt.% of such impurities, preferably at most or less than 1.5 wt.%, most preferably at most 1.0 wt.% of such impurities based on the total mass of the odorant mixture.

[0104] The diastereomerically enriched fragrance mixtures are suitable as fragrances or as additives to fragrance preparations. These diastereomerically enriched fragrance mixtures are also used in consumer goods containing these compounds and mixtures.

[0105] In a third aspect, the present invention relates to the use of the diastereomerically enriched fragrance mixture as a fragrance or for the production of a fragrance preparation. Thus, the present invention relates to the use of the fragrance mixture according to the invention as a fragrance, in particular with an optimized, intense, radiant, natural, and transparent floral scent, or for the production of a fragrance preparation, in particular with such an optimized floral scent profile.

[0106] Another object of the present invention relates to an odorant preparation containing a sensorially effective amount of the diastereomerically enriched odorant mixture, as defined above.

[0107] Within the scope of the present invention, an odorant preparation is a mixture of various substances, which is produced from the respective substances according to a recipe or formula using a predetermined method. Such preparations are specifically manufactured and used for the purpose of conveying, modifying, or enhancing a desired odor impression that is usually perceived as pleasant or otherwise positive.

[0108] An odorant preparation according to the invention, particularly in the form of a perfume oil, preferably with an optimized floral scent as described herein, consists of or comprises the diastereomerically enriched odorant mixture according to the invention, as defined above, and one, two, three, four, five, six, seven, eight, nine, ten, or more further odorant(s). In this way, mixtures with particularly interesting, intense, and natural floral scents can be easily created, which, unlike most previous magnolan-based odorant preparations, do not exhibit technical or plastic-like scents. The odorant mixtures according to the invention can be used as a single substance or combined with a multitude of further odorants in numerous products to create or generate a distinctive odor impression.

[0109] Fragrance substances and / or flavoring substances that are suitable for use in a fragrance preparation according to the invention, as defined above, can be found, for example, in S. Arctander, "Perfume and Flavor Materials", Vol. I and II, Montclair, NJ 1969, self-published, or K. Bauer et al., "Common Fragrance and Flavor Materials", 4th Edition, Wiley-VCH, Weinheim 2001.

[0110] Specifically, the following should be mentioned: extracts from natural raw materials such as essential oils, concretes, absolutes, resins, resinoids, balsams, tinctures such as amber tincture; amyris oil; angelica seed oil; angelica root oil; anise oil; valerian oil; basil oil; treemoss absolute; bay oil; mugwort oil; benzoin oil; bergamot oil; beeswax absolute; birch tar oil; bitter almond oil; savory oil; buchu leaf oil; cabreuva oil; cade oil; calamus oil; camphor oil; cananga oil; cardamom oil; cascarilla oil; cassia oil; cassia absolute; castoreum absolute; cedar leaf oil; cedarwood oil; cistus oil; citronella oil; lemon oil; copaiba balsam; copaiba balsam oil; coriander oil; costus root oil; cumin oil; cypress oil; davana oil; dill herb oil; dill seed oil; Eau de brouts absolute; oakmoss absolute; elemi oil; tarragon oil; Eucalyptus citriodora oil; eucalyptus oil; fennel oil; spruce needle oil; galbanum oil; galbanum resin; geranium oil; grapefruit oil; guaiac wood oil; Gurjun balm; Gurjun balsam oil; Helichrysum absolute; helichrysum oil; ginger oil; orris root absolute;Iris root oil; Jasmine absolute; Calamus oil; Blue chamomile oil; Roman chamomile oil; Carrot seed oil; Cascarilla oil; Pine needle oil; Spearmint oil; Caraway oil; Labdanum oil; Labdanum absolute; Labdanum resin; Lavandin absolute; Lavandin oil; Lavender absolute; Lavender oil; Lemongrass oil; Lovage oil; Distilled lime oil; Pressed lime oil; Linaloe oil; Litsea cubeba oil; Bay leaf oil; Mace oil; Marjoram oil; Mandarin oil; Massoi bark oil; Mimosa absolute; Musk seed oil; Musk tincture; Clary sage oil; Nutmeg oil; Myrrh absolute; Myrrh oil; Myrtle oil; Clove leaf oil; Clove flower oil; Neroli oil; Frankincense absolute; Frankincense oil; Opopanax oil; Orange blossom absolute; orange oil; oregano oil; palmarosa oil; patchouli oil; perilla oil; Peruvian balsam oil; parsley leaf oil; parsley seed oil; petitgrain oil; peppermint oil; pepper oil; pimento oil; pine oil; poley oil; rose absolute; rosewood oil; rose oil; rosemary oil; Dalmatian sage oil; Spanish sage oil; sandalwood oil; celery seed oil; spike lavender oil; star anise oil; styrax oil;Marigold oil; fir needle oil; tea tree oil; turpentine oil; thyme oil; tolu balsam; tonka bean absolute; tuberose absolute; vanilla extract; violet leaf absolute; verbena oil; vetiver oil; juniper berry oil; wine yeast oil; wormwood oil; wintergreen oil; ylang oil; hyssop oil; civet absolute; cinnamon leaf oil; cinnamon bark oil, and fractions thereof or isolated components thereof; Individual fragrance components from the group of hydrocarbons, such as 3-carene; α-pinene; β-pinene; α-terpinene; γ-terpinene; p-cymene; bisabolene; camphene; caryophyllene; cedrene; farnesene; limonene; longifolene; myrcene; ocimene; valencene; (E,Z)-1,3,5-undecatriene; styrene; diphenylmethane; and the aliphatic alcohols, such as hexanol; octanol; 3-octanol; 2,6-dimethylheptanol; 2-methyl-2-heptanol; 2-methyl-2-octanol; (E)-2-hexenol; 1-octen-3-ol; Mixture of 3,4,5,6,6-pentamethyl-3 / 4-hepten-2-ol and 3,5,6,6-tetramethyl-4-methyleneheptan-2-ol; (E,Z)-2,6-nonadienol; 3,7-dimethyl-7-methoxyoctan-2-ol; 9-decenol; 10-undecenol; 4-methyl-3-decen-5-ol; the aliphatic aldehydes and their acetals, such as e.g.Hexanal; Heptanal; Octanal; Nonanal; Decanal; Undecanal; Dodecanal; 2-Methyloctanal; 2-Methylnonanal; (E)-2-Hexenal; (Z)-4-Heptenal; 2,6-Dimethyl-5-heptenal; 10-Undecenal; (E)-4-Decenal; 2-Dodecenal; 2,6,10-Trimethyl-9-undecenal; 2,6,10-Trimethyl-5,9-undecadienal; Heptanaldiethylacetal; 1,1-Dimethoxy-2,2,5-trimethyl-4-hexene; Citronellyloxyacetaldehyde; 1-(1-Methoxy-propoxy)-(E / Z)-3-hexene; the aliphatic ketones and their oximes, such as 2-heptanone; 2-Octanone; 3-Octanone; 2-Nonanone; 5-Methyl-3-heptanone; 5-Methyl-3-heptanone oxime; 2,4,4,7-Tetramethyl-6-octen-3-one; 6-Methyl-5-hepten-2-one; of the aliphatic sulfur-containing compounds, such as 3-Methylthiohexanol; 3-Methylthiohexyl acetate; 3-Mercaptohexanol; 3-Mercaptohexyl acetate; 3-Mercaptohexyl butyrate; 3-Acetylthiohexyl acetate; 1-Menthen-8-thiol; of the aliphatic nitriles, such as2-Nonenonitrile; 2-Undecenonitrile; 2-Tridecenitrile; 3,12-Tridecadienitrile; 3,7-Dimethyl-2,6-octadienonitrile; 3,7-Dimethyl-6-octenonitrile; of aliphatic carboxylic acids and their esters, such as (E)- and (Z)-3-hexenyl formate; ethyl acetoacetate; isoamyl acetate; 3,5,5-trimethylhexyl acetate; 3-methyl-2-butenyl acetate; (E)-2-hexenyl acetate; (E)- and (Z)-3-hexenyl acetate; octyl acetate; 3-octyl acetate; 1-octen-3-yl acetate; ethyl butyrate; butyl butyrate; isoamyl butyrate; hexyl butyrate; (E)- and (Z)-3-hexenyl isobutyrate; hexyl crotonate; ethyl isovalerianate; ethyl 2-methylpentanoate; ethyl hexanoate; allyl hexanoate; ethyl heptanoate; allyl heptanoate; ethyl octanoate; ethyl (E,Z)-2,4-decadienoate; methyl 2-octinate; methyl 2-noninate; allyl 2-isoamyloxyacetate; methyl 3,7-dimethyl-2,6-octadienoate; 4-methyl-2-pentyl crotonate; the acyclic terpene alcohols, such asgeraniol; Nerol; lavadulol; nerolidol; farnesol; tetrahydrolinalool; tetrahydrogeraniol; 2,6-Dimethyl-7-octen-2-ol; 2,6-Dimethyloctan-2-ol; 2-Methyl-6-methylene-7-octen-2-ol; 2,6-Dimethyl-5,7-octadien-2ol; 2,6-Dimethyl-3,5-octadien-2-ol; 3,7-Dimethyl-4,6-octadien-3-ol; 3,7-Dimethyl-1,5,7-octatrien-3-ol; 2,6-Dimethyl-2,5,7-octatrien-1-ol; as well as their formates, acetates, propionates, isobutyrates, butyrates, isovalerianates, pentanoates, hexanoates, crotonates, tiglinates and 3-methyl-2-butenoates; acyclic terpene aldehydes and ketones, such as citronellal; 7-methoxy-3,7-dimethyloctanal; 2,6,10-trimethyl-9-undecenal; geranial acetone; as well as the dimethyl and diethyl acetals of geranial and neral; cyclic terpene alcohols, such asMenthol; Isopulegol; alpha-terpineol; Terpinenol-4; Menthan-8-ol; Menthan-1-ol; Menthan-7-ol; Borneol; Isoborneol; Linalool oxide; Nopol; Cedrol; Ambrinol; Vetiverol; Guajol; and their formates, acetates, propionates, isobutyrates, butyrates, isovalerates, pentanoates, hexanoates, crotonates, tiglinates, and 3-methyl-2-butenoate; the cyclic terpene aldehydes and ketones, such as menthone; isomenthone; 8-mercaptomenthan-3-one; carvone; camphor; fenchone; alpha-ionone; beta-ionone; alpha-n-methylionone; beta-n-methylionone; alpha-isomethylionone; beta-isomethylionone; alpha-iron; beta-Damascenone; 1-(2,4,4-Trimethyl-2-cyclohexen-1-yl)-2-buten-1-one; 1,3,4,6,7,8a-Hexahydro-1,1,5,5-tetramethyl-2H-2,4a-methano-naphthalen-8-(5H)-one; 2-Methyl-4-(2,6,6-trimethyl-1-cyclohexen-1-yl)-2-butenal; Nootkatone; Dihydronootkatone; 4,6,8-Megastigmatrien-3-one; alpha-Sinensal; beta-Sinensal; acetylated cedarwood oil (methylcedryl ketone); the cyclic alcohols, such as e.g.4-tert-Butylcyclohexanol; 3,3,5-Trimethylcyclohexanol; 3-Isocamphylcyclohexanol; 2,6,9- T rimethyl-Z2,Z5, E9-cyclododecatrien-1-ol; 2-Isobutyl-4-methyltetrahydro-2H-pyran-4-ol; der cycloaliphatischen Alkohole, wie z.B. alpha,3,3-Trimethylcyclohexylmethanol; 1-(4-Isopropylcyclohexyl)ethanol; 2-Methyl-4-(2,2,3-trimethyl-3-cyclopent-1-yl)butanol; 2-Methyl-4-(2,2,3-trimethyl-3-cyclopent-1-yl)-2-buten-1-ol; 3-Methyl-5-(2,2,3-trimethyl-3-cyclopent-1-yl)pentan-2-ol; 3-Methyl-5-(2,2,3-trimethyl-3-cyclopent-1-yl)-4-penten-2-ol; 3,3-Dimethyl-5-(2,2,3-trimethyl-3-cyclopent-1-yl)-4-penten-2-ol; 1-(2,2,6-Trimethylcyclohexyl)pentan-3-ol; 1-(2,2,6-Trimethylcyclohexyl)hexan-3-ol; der cyclischen und cycloaliphatischen Ether, wie z.B. Cineol; Cedrylmethylether; Cyclododecylmethylether; 1,1-Dimethoxycyclododecan; (Ethoxymethoxy)-cyclododecan; alpha-Cedrenepoxid; 3a,6,6,9a-Tetramethyldodecahydro-naphtho[2,1b]furan; 3a-Ethyl-6,6,9a-trimethyldodecahydronaphtho[2,1b]furan; 1,5,9-Trimethyl-13-oxabicyclo[10.1.0]trideca-4,8-dien; Rosenoxid; 2-(2,4-Dimethyl-3-cyclohexen-1-yl)-5methyl-5-(1-methylpropyl)-1,3-dioxan; der cyclischen und makrocyclischen Ketone, wie z.B. 4-tert.-Butylcyclohexanon; 2,2,5-Trimethyl-5-pentylcyclopentanon; 2-Heptylcyclopentanon; 2-Pentylcyclopentanon; 2-Hydroxy-3-methyl-2-cyclopenten-1-on; 3-Methyl-cis-2-penten-1-yl-2-cyclopenten-1-on; 3-Methyl-2-pentyl-2-cyclopenten-1-on; 3-Methyl-4-cyclopentadecenon; 3-Methyl-5-cyclopentadecenon; 3-Methylcyclopentadecanon; 4-(1-Ethoxyvinyl)-3,3,5,5-tetramethylcyclohexanon; 4-tert.-Pentylcyclohexanon; 5-Cyclohexadecen-1-on; 6,7-Dihydro-1,1,2,3,3-pentamethyl-4(5H)-indanon; 8-Cyclohexadecen-1-on; 9-Cycloheptadecen-1-on; Cyclopentadecanon; Cyclohexadecanon; der cycloaliphatischen Aldehyde, wie z.B. 2-Methyl-4-(2,2,6-trimethyl-cyclohexen-1-yl)-2-butenal; 4-(4-Hydroxy-4-methylpentyl)-3-cyclohexencarbaldehyd; 4-(4-Methyl-3-penten-1-yl)-3-cyclohexencarbaldehyd; der cycloaliphatischen Ketone, wie z.B.1-(3,3-Dimethylcyclohexyl)-4-penten-1-on; 2,2-Dimethyl-1-(2,4-dimethyl-3-cyclohexen-1-yl)-1-propanon; 1-(5,5-Dimethyl-1-cyclohexen-1-yl)-4-penten-1-on; 2,3,8,8-Tetramethyl-1,2,3,4,5,6,7,8-octahydro-2-naphtalenylmethylketon; Methyl-2,6,10-trimethyl-2,5,9-cyclododecatrienylketon;tert.-Butyl-(2,4-dimethyl-3-cyclohexen-1-yl)keton; der Ester cyclischer Alkohole, wie z.B. 2-tert-Butylcyclohexylacetat; 4-tert.-Butylcyclohexylacetat; 2-tert-Pentylcyclohexylacetat; 4-tert.-Pentylcyclohexylacetat; 3,3,5-Trimethylcyclohexylacetat; Decahydro-2-naphthylacetat; 2-Cyclopentylcyclopentylcrotonat; 3-Pentyltetrahydro-2H-pyran-4-ylacetat; Decahydro-2,5,5,8a-tetramethyl-2-naphthylacetat; 4,7-Methano-3a,4,5,6,7,7a-hexahydro-5, bzw. 6-indenylacetat; 4,7-Methano-3a,4,5,6,7,7a-hexahydro-5, bzw. 6-indenyl-propionat; 4,7-Methano-3a,4,5,6,7,7a-hexahydro-5- bzw. 6-inden-ylisobutyrat; 4,7-Methanooctahydro-5- bzw. 6-indenylacetat; der Ester cycloaliphatischer Alkohole, wie z.B.1-Cyclohexyl ethylcrotonate; the esters of cycloaliphatic carboxylic acids, such as allyl-3-cyclohexylpropionate; allylcyclohexyloxyacetate; cis- and trans-methyldihydrojasmonate; cis- and trans-methyljasmonate; methyl-2-hexyl-3-oxocyclopentanecarboxylate; ethyl-2-ethyl-6,6-dimethyl-2-cyclohexenecarboxylate; ethyl-2,3,6,6-tetramethyl-2-cyclohexenecarboxylate; ethyl-2-methyl-1,3-dioxolane-2-acetate; the aliphatic alcohols, such as benzyl alcohol; 1-phenylethyl alcohol; 3-phenylpropanol; 2-phenylpropanol; 2-phenoxyethanol; 2,2-dimethyl-3-phenylpropanol; 2,2-Dimethyl-3-(3-methylphenyl)propanol; 1,1-Dimethyl-2-phenylethyl alcohol; 1,1-Dimethyl-3-phenylpropanol; 1-Ethyl-1-methyl-3-phenylpropanol; 2-Methyl-5-phenylpentanol; 3-Methyl-5-phenylpentanol; 3-Phenyl-2-propen-1-ol; 4-Methoxybenzyl alcohol; 1-(4-Isopropylphenyl)ethanol; the esters of aliphatic alcohols and aliphatic carboxylic acids, such as e.g.Benzylacetat; Benzylpropionat; Benzylisobutyrat; Benzylisovalerianat; 2-Phenylethylacetat; 2-Phenylethylpropionat; 2-Phenylethylisobutyrat; 2-Phenylethylisovalerianat; 1-Phenylethylacetat; alpha-Trichlormethylbenzylacetat; alpha,alpha-Dimethylphenylethylacetat; alpha,alpha-Dimethylphenylethylbutyrat; Cinnamylacetat; 2-Phenoxyethylisobutyrat; 4-Methoxybenzylacetat; der aliphatischen Ether, wie z.B. 2-Phenylethylmethylether; 2-Phenylethylisoamylether; 2-Phenylethyl-1-ethoxyethylether; Phenylacetaldehyddimethylacetal; Phenylacetaldehyddiethylacetal; Hydratropaaldehyddimethylacetal; Phenylacetaldehydglycerinacetal; 2,4,6-Trimethyl-4-phenyl-1,3-dioxan; der aromatischen und aliphatischen Aldehyde, wie z.B. Benzaldehyd; Phenylacetaldehyd; 3-Phenylpropanal; Hydratropaaldehyd; 4-Methylbenzaldehyd; 4-Methylphenylacetaldehyd; 3-(4-Ethylphenyl)-2,2-dimethylpropanal; 2-Methyl-3-(4-isopropylphenyl)propanal; 2-Methyl-3-(4-isobutylphenyl)propanal; 3-(4-tert.-Butylphenyl)propanal; Zimtaldehyd; alpha-Butylzimtaldehyd; alpha-Hexylzimtaldehyd; 3-Methyl-5-phenylpentanal; 4-Methoxybenzaldehyd; 4-Hydroxy-3-methoxybenzaldehyd; 4-Hydroxy-3-ethoxybenzaldehyd; 3,4-Methylendioxybenzaldehyd; 3,4-Dimethoxybenzaldehyd; 2-Methyl-3-(4-methoxyphenyl)propanal;-Methyl-3-(4-methylendioxyphenyl)propanal; der aromatischen und aliphatischen Ketone, wie z.B. Acetophenon; 4-Methylacetophenon; 4-Methoxyacetophenon; 4-tert.-Butyl-2,6-dimethylacetophenon; 4-Phenyl-2-butanon; 4-(4-Hydroxyphenyl)-2-butanon; 1-(2-Naphthalenyl)ethanon; 2-Benzofuranylethanon; (3-Methyl-2-benzofuranyl)ethanon; Benzophenon; 1,1,2,3,3,6-Hexamethyl-5-indanylmethylketon; 6-tert.-Butyl-1,1-di-methyl-4-indanylmethylketon; 1-[2. ,3-dihydro-1,1,2,6-tetramethyl-3-(1-methylethyl)-1H-5-indenyl]ethanone; 5',6',7',8'-Tetrahydro-3',5',5',6',8',8'-hexamethyl-2-acetonaphthone; of aromatic and aliphatic carboxylic acids and their esters, such as benzoic acid; phenylacetic acid; methyl benzoate; ethyl benzoate; hexyl benzoate; benzyl benzoate; methylphenyl acetate; ethylphenyl acetate; geranylphenyl acetate; phenylethylphenyl acetate; methyl cinnamate; ethyl cinnamate; benzyl cinnamate; phenylethyl cinnamate; cinnamyl cinnamate; allylphenoxyacetate; methyl salicylate; hexyl salicylate; cyclohexyl salicylate; cis-3-hexenyl salicylate; benzyl salicylate; Phenylethyl salicylate; Methyl 2,4-dihydroxy-3,6-dimethyl benzoate; Ethyl 3-phenyl glycidate; Ethyl 3-methyl-3-phenyl glycidate; of nitrogen-containing aromatic compounds, such as 2,4,6-trinitro-1,3-dimethyl-5-tert-butylbenzene; 3,5-dinitro-2,6-dimethyl-4-tert.-butylacetophenone; cinnamic acid nitrile; 3-methyl-5-phenyl-2-pentenonitrile; 3-methyl-5-phenylpentanonitrile; methyl anthranilate; methyl-N-methyl anthranilate; Schiff bases of methyl anthranilate with 7-hydroxy-3,7-dimethyloctanal, 2-methyl-3-(4-tert-butylphenyl)propanal or 2,4-dimethyl-3-cyclohexenecarbaldehyde; 6-isopropyl quinoline; 6-isobutyl quinoline; 6-sec-butyl quinoline; 2-(3-phenylpropyl)pyridine; indole; skatole; 2-methoxy-3-isopropylpyrazine; 2-isobutyl-3-methoxypyrazine; of phenols, phenyl ethers and phenyl esters, such as estragole; anethole; eugenyl methyl ether; isoeugenol; Isoeugenyl methyl ether; thymol; carvacrol; diphenyl ether; beta-naphthyl methyl ether; beta-naphthyl ethyl ether; beta-naphthyl isobutyl ether; 1,4-dimethoxybenzene; eugenyl acetate; 2-methoxy-4-methylphenol; 2-ethoxy-5-(1-propenyl)phenol; p-cresylphenyl acetate; of heterocyclic compounds, such as e.g.2,5-Dimethyl-4-hydroxy-2H-furan-3-on; 2-Ethyl-4-hydroxy-5-methyl-2H-furan-3-on; 3-Hydroxy-2-methyl-4H-pyran-4-on; 2-Ethyl-3-hydroxy-4H-pyran-4-on; der Lactone, wie z.B. 1,4-Octanolid; 3-Methyl-1,4-octanolid; 1,4-Nonanolid; 1,4-Decanolid; 8-Decen-1,4-olid; 1,4-Undecanolid; 1,4-Dodecanolid; 1,5-Decanolid; 1,5-Dodecanolid;4-Methyl-1,4-decanolid; 1,15-Pentadecanolid; 1,16-Hexadecanolid; 9-Hexadecen-1,16-olid; 10-Oxa-1,16-hexadecanolid; 11-Oxa-1,16-hexadecanolid; 12-Oxa-1,16-hexadecanolid; Ethylen-1,12-dodecandioat; Ethylen-1,13-tridecandioat; 2,3-Dihydrocumarin; Octahydrocumarin. .

[0111] In an odorant preparation according to the invention, in particular a perfume oil, the amount of the diastereomerically enriched odorant mixture, as defined above, is in a range of 0.0001 wt.% to 40 wt.%, preferably in the range of 0.001 wt.% to 25 wt.%, and particularly preferably in a range of 0.0001 wt.% to 10 wt.% or 5 wt.% based on the total weight of the odorant preparation.

[0112] In addition to their use as liquids in solutions or emulsions, the fragrance mixtures or fragrance preparations according to the invention, containing these fragrance mixtures, for example perfume oils, can be adsorbed onto solids or (micro)encapsulated in carrier materials. These dosage forms can ensure both a fine distribution of the fragrances in the product and a controlled release during application. Such solids can be porous inorganic materials such as light sulfate, silica gels, zeolites, gypsum, clays, clay granules, aerated concrete, etc., or organic materials such as woods, cellulose-based substances, sugars, or plastics such as PVC, polyvinyl acetates, or polyurethanes.

[0113] Encapsulation products can be, for example, spray-dried, as an inclusion complex, or as an extrusion product.

[0114] In the context of the present invention, a "sensorially effective quantity" means that the odorant or the diastereomerically enriched odorant mixture is present in such a sufficient quantity that the resulting product, when used, exhibits the sensory properties of the odorant or the odorant mixture according to the invention. Thus, a sensorially effective quantity is understood to be a proportion of the odorant mixture according to the invention that is sufficient to produce the effects described therein, i.e., for example, highlighting or emphasizing a pleasant and optimized floral scent and / or a masking effect.

[0115] Furthermore, the present invention relates to the use of the diastereomerically enriched odorant mixture according to one of the preceding aspects in a sensorially effective quantity for conveying, modifying, or enhancing a floral odor note of a perfumed product or for producing a perfumed product. In this context, "enhancing" means to highlight or emphasize a particular fragrance note, especially odors or odor notes of the optimized, intense, and naturally "clean" floral type described herein.

[0116] Since floral fragrances, i.e., fragrances with a "clean" floral note, are particularly preferred and in demand in the perfumery industry, the fragrances and fragrance preparations described in the present invention, including the diastereomerically enriched fragrance mixture, are especially suitable for such applications. In this context, fragrance notes of a technical type or those reminiscent of plastic are generally perceived as negative and therefore disturbing. Because the present fragrance mixture can be produced simply, in just a few steps, and simultaneously with high yield and high purity, a fragrance mixture can be provided that does not exhibit the aforementioned negatively perceived odor notes and is thus suitable for a variety of applications, especially for conveying, modifying, or enhancing an intensely radiant and "clean" floral fragrance note.

[0117] In this context, "clean" refers to a scent that does not have any technical, plastic-like, or otherwise negatively perceived scent characteristics that distract from the floral note and are not perceived as natural.

[0118] The fragrances or fragrance mixtures and preparations described herein show a significant enhancement of the intense, natural and "clean" floral fragrance notes even at low doses.

[0119] It was surprisingly observed that the fragrance mixture described herein exhibits excellent stability properties and can therefore be readily incorporated into a wide variety of product formulations. Consequently, this fragrance mixture is particularly suitable for the production of numerous perfumed products, such as shampoos, creams, soaps, deodorants, cleaning agents, and the like.

[0120] Ultimately, the present invention therefore relates to a perfumed product comprising the diastereomerically enriched fragrance mixture as described above, or a corresponding fragrance preparation in concentrated form, in solutions, or in any other modified form for the manufacture of consumer goods or perfumed products within the meaning of the invention, such as perfume extracts, eau de parfums, eau de toilettes, aftershaves, eau de colognes, preshave products, splash colognes, and perfumed refreshing wipes, as well as for the perfumery of acidic, alkaline, and neutral cleaning agents, such as…Floor cleaners, window cleaners, dishwashing liquids, bathroom and sanitary cleaners, scouring creams, solid and liquid toilet cleaners, powder and foam carpet cleaners, liquid detergents, powder detergents, laundry pretreatment products such as bleaches, soaking agents and stain removers, fabric softeners, washing soaps, washing tablets, disinfectants, surface disinfectants, as well as air fresheners in liquid, gel or solid form, aerosol sprays, waxes and polishes such as furniture polishes, floor waxes, shoe polishes, and personal care products such as solid and liquid soaps, shower gels, shampoos, shaving soaps, shaving foams, bath oils, cosmetic emulsions of the oil-in-water, water-in-oil and water-in-oil-in-water type, such as...Skin creams and lotions, face creams and lotions, sun protection creams and lotions, after-sun creams and lotions, hand creams and lotions, foot creams and lotions, hair removal creams and lotions, aftershave creams and lotions, tanning creams and lotions, hair care products such as hairsprays, hair gels, hair lotions, hair conditioners, permanent and semi-permanent hair dyes, hair styling products such as cold waves and hair straightening products, hair tonics, hair creams and lotions, deodorants and antiperspirants such as underarm sprays, roll-ons, deodorant sticks, deodorant creams or decorative cosmetic products.

[0121] Consequently, the present invention ultimately also relates to a perfumed product comprising the diastereomerically enriched fragrance mixture as described above, or a corresponding fragrance preparation comprising therein. Examples

[0122] The present invention is described in more detail below with reference to exemplary embodiments.

[0123] Preparation of a diastereomerically enriched fragrance mixture according to the procedure described herein: First, an emulsion of dilute sulfuric acid and toluene was placed in a reaction vessel. Then, at a temperature of 5 °C, the reactants paraldehyde and indene were added and stirred for 5 hours. Subsequently, the reaction product was washed three times with water and the organic phase was distilled off.

[0124] In accordance with step (a) of the procedure described herein, the resulting reaction product was fed into a thin-film evaporator. In the first stage of the thin-film distillation, the crude product was purified of any residual solvents and unreacted reactants at 200 mbar and a jacket temperature of 165 °C. The purified crude product was then collected by distillation at 1 mbar and a jacket temperature of 190 °C (second stage of the thin-film distillation).

[0125] The crude product thus obtained was then subjected to fine distillation (step (b)). For this purpose, the crude product was distilled in a distillation apparatus with Sulzer BX as packing material over 20 stages in a continuous process. The reflux ratio was approximately 10:1, the head temperature approximately 138 °C to 139 °C, and the distillation was carried out at a reduced pressure of approximately 10 mbar.

[0126] The product thus obtained exhibits the enantiomeric pairs in the following proportions: the ratio of enantiomeric pair (I) to enantiomeric pair (II) in the resulting fragrance mixture is 96.894 to 0.577, while the ratio of enantiomeric pair (I) to enantiomeric pair (III) is 96.894 to 0.047. Consequently, the proportion of enantiomeric pair (I) compared to the totality of compounds according to formula (A), i.e., based on the sum of enantiomeric pairs (I), (II), and (III), in the resulting fragrance mixture is at least 95 wt% and exhibits a corresponding diastereomeric purity. In this case, the chemical purity, i.e., the sum of all diastereomers of formula (A) in relation to all other impurities, was 97.5 to 2.5.

[0127] In a second example using the same procedure, the ratio of enantiomeric pairs (I) to (II) to (III) was 97.971 to 0.979 to 0.072. Here too, the proportion of enantiomeric pair (I) is over 95 wt% relative to the sum of enantiomeric pairs (I), (II), and (III). Furthermore, the resulting product exhibits a chemical purity of over 98.5 wt%, meaning it contains less than 1 wt% impurities (see Figure 3 ). Analytics:

[0128] Gas chromatographic analysis of the first example revealed a composition of 96.894 wt% of enantiomeric pair (I), 0.577 wt% of enantiomeric pair (II), and 0.047 wt% of enantiomeric pair (III). In the second example, a composition corresponding to the following proportions was detected: 97.971% of enantiomeric pair (I), 0.979% of enantiomeric pair (II), and 0.072% of enantiomeric pair (III).

[0129] The corresponding values ​​were obtained using Thermo Fisher Scientific gas chromatographs (TRACE1300Series) with polyethylene glycol as the column material.

[0130] The figures show the corresponding NMR measurements of the first example and a gas chromatographic analysis of the second example.

[0131] NMR data of the first example: H-NMR: 7.38 m (1H), 7.25 m (2H), 7.21 m (1H), 5.46 d, J=6.60 (1H), 4.75 q, J=5.09 (1H), 3.32 dq, J= 10.38, 6.13 (1H), 2.92 ddd, J=15.89, 6.52, 1.25 (1H), 2.49 d, J=16.00 (1H), 2.40 dt, J=10.44, 6.58 (1H), 1.35 d, J=5.11 (3H), 1.27 d, J=6.15 (3H).

[0132] Furthermore, the resulting odorant mixture does not exhibit a measurable rotation value, so it can be concluded that the enantiomers of the respective enantiomeric pairs are each in racemic form to each other, i.e., the enantiomeric pairs (I), (II) and (III) are each racemic. Comparative example:

[0133] While isomers (I) and (II) are present in a ratio of at least 10 : 1 to each other, a comparative example shows that even changes in the reflux ratio to 1 : 1 and in the head temperature to approximately 141 °C to 142 °C, under otherwise identical distillation conditions, result in a quantitative ratio of the enantiomeric pair (I) to the enantiomeric pair (II) in the fragrance mixture of only 1 : 2 to 2 : 1.

[0134] Consequently, it was possible to provide a diastereomerically enriched fragrance mixture according to the invention, which has the preferred and optimized floral fragrance, by skillfully choosing the distillation conditions. Scent description:

[0135] To determine the olfactory properties, the individual enantiomeric pairs (I), (II), and (III) were obtained separately by chromatographic separation and evaluated for their odor by a test panel of eight test subjects. The individual enantiomeric pairs exhibited the following odor profiles: The odor of enantiomeric pair (I) can be described as essentially floral, rosy, transparent, radiant, and geranium-like, while enantiomeric pair (II) evokes a floral, green, somewhat technical, grapefruit-like, and weaker odor impression compared to enantiomeric pair (I). Enantiomeric pair (III), on the other hand, exhibits an essentially floral, technical, unclean, and plastic-like odor profile.

[0136] The results of the olfactory function test are shown in Table 1 below: Table 1: Fragrance description Commercially available Magnolan Isomer mixture according to claim 1 Enantiome ren-pair 1 Enantiomer en-pair 2 Enantiome ren-pair 3 rose 6 8 8 5 4 lily of the valley 6 5 6 7 3 Orris / Violets 2 0 0 2 2 Leafy greens 5 2 2 6 5 Jasmine / Ylang 3 2 2 3 2 Orange blossom 3 1 1 3 2 Fruity 5 3 2 6 5 Indole-like 3 0 0 2 5 plastic 3 1 0 1 6

[0137] Table 1 shows that the enantiomeric pair (III) and the commercially available magnolane produced in the comparison example exhibit a strong plastic odor. In contrast, the isomeric mixture of the present invention according to claim 1 has a significantly lower plastic odor and a more radiant rose note. Thus, the odor of the commercially available magnolane has been improved.

[0138] The odor of the overall racemic product, i.e., the odorant mixture according to the inventive examples, could in both cases be described as somewhat warmer, more intense, and more naturally floral, rosy, transparent, radiant, and smelling of geranium, whereas comparative odorant mixtures with enantiomeric compositions deviating from the present description are characterized by the odorant properties of enantiomeric pairs (II) and / or (III) and consequently produced a somewhat technical, grapefruit-scented, and, compared to enantiomeric pair (I), weaker, i.e., less intense, less clean, and overall less floral odor impression, which in some cases even exhibits intense technical or even plastic-like and unclean notes. Therefore, the purified products according to the invention are preferable.

[0139] Commercially available Magnolan products, such as the Magnolan produced in the comparison example or the raw Magnolan product, also have a somewhat technical and plastic-like odor, which can thus be described as floral, green, somewhat rosy, somewhat technical and smelling of grapefruit and plastic.

[0140] In the In contrast, the diastereomerically enriched odorant mixtures of the first and second aspects obtained from the method described herein exhibit an extremely intense, radiant, balanced, natural, "clean" floral, rosy, transparent, somewhat warmer and geranium-scented odor, which is generally perceived as more pleasant, balanced and "clean" compared to the products mentioned above, and has no technical or plastic-like odor notes.

[0141] Accordingly, the process described herein has demonstrated an efficient, simple, and gentle distillation method for the effective and gentle distillation enrichment of the enantiomeric pair (I) and the provision of the diastereomerically enriched odorant mixture comprising the compounds of general formula (A) according to the first and second aspects in high purity and yield. In particular, it was surprisingly possible to enrich the enantiomeric pair (I) in the odorant mixture according to the invention to a proportion of over 95 wt% based on the sum of the enantiomeric pairs (I), (II), and (III), thus effectively optimizing the resulting odor impression.

Claims

1. Distillative method for preparing a diastereomer-enriched fragrance mixture comprising compounds of general formula (A): wherein the fragrance mixture comprises the following, mutually diastereomeric, enantiomer pairs: wherein the quantitative ratio between enantiomer pair (I) and enantiomer pair (II) is at least 10:1; wherein the quantitative ratio between enantiomer pairs (I) and (III) is at least 50:1; and wherein the method comprises the following distillation steps: (a) separating off, by distillation, a crude product comprising compounds of general formula (A) in a first distillation step; (b) then finely distilling the crude product over one or more distillation steps to concentrate enantiomer pair (I) relative to enantiomer pairs (II) and (III), the fine distillation comprising at least 15 separation stages.

2. Method for preparing a diastereomer-enriched fragrance mixture according to claim 1, which further comprises, prior to the distillation steps: - providing paraldehyde of general formula (IV) or acetaldehyde; and - reacting it with indene of general formula (V) under acidic catalysis in a solvent, the reaction between paraldehyde and indene taking place at temperatures below 10°C; and - obtaining the crude product comprising compounds of general formula (A).

3. Method for preparing a diastereomer-enriched fragrance mixture according to any one of the preceding claims 1 or 2, wherein the fine distillation in the distillation method takes place in a continuous process.

4. Method for preparing a diastereomer-enriched fragrance mixture according to any one of the preceding claims 1 to 3, wherein the fine distillation in the distillation method has a reflux ratio of at least 5:1.

5. Method for preparing a diastereomer-enriched fragrance mixture according to any one of the preceding claims 1 to 4, wherein the fine distillation in the distillation method is carried out at temperatures between 120°C and 150°C.

6. Method for preparing a diastereomer-enriched fragrance mixture according to any one of the preceding claims 1 to 5, wherein the fine distillation in the distillation method is carried out at a reduced pressure of about 1 to 100 mbar.

7. Method for preparing a diastereomer-enriched fragrance mixture according to any one of the preceding claims 1 to 6, wherein the first distillation step is a thin film distillation.

8. Method for preparing a diastereomer-enriched fragrance mixture according to claim 7, wherein the thin film distillation comprises two stages: - separating off the solvent at a reduced pressure of about 1 mbar to 400 mbar; and - extracting the crude product comprising compounds of general formula (A) at a reduced pressure of about 0 mbar to 100 mbar.

9. Method for preparing a diastereomer-enriched fragrance mixture according to any one of the preceding claims 7 or 8, wherein the first stage of the thin film distillation is carried out at a jacket temperature of between 120°C and 200°C, and wherein the second stage of the thin film distillation is carried out at a jacket temperature of between 150°C and 250°C.

10. Diastereomer-enriched fragrance mixture comprising compounds of general formula (A): wherein the compounds of formula (A) comprise the following, mutually diastereomeric, enantiomer pairs of formulae (I), (II) and (III): wherein the quantitative ratio between enantiomer pair (I) and enantiomer pair (II) is at least 10:1; and wherein the quantitative ratio between enantiomer pairs (I) and (III) is at least 50:1.

11. Diastereomer-enriched fragrance mixture according to claim 10, wherein the fragrance mixture comprises, in total, at least 96.5% by weight of enantiomer pairs (I), (II) and (III).

12. Use of the diastereomer-enriched fragrance mixture according to any one of the preceding claims 10 or 11 as a fragrance or for preparing a fragrance composition.

13. Fragrance composition containing a sensorially effective amount of the diastereomer-enriched fragrance mixture according to any one of the preceding claims 10 or 11.

14. Use of the diastereomer-enriched fragrance mixture according to any one of the preceding claims 10 or 11 in a sensorially effective amount for imparting, modifying or enhancing a floral scent of a perfumed product or for preparing a perfumed product.

15. Perfumed product, comprising the diastereomer-enriched fragrance mixture according to claim 10 or 11 or a fragrance composition according to claim 13.