Cyclopropanated sandalwood compounds

Abstract

The present invention is in the field of perfumery and relates to novel perfume compounds according to general formula (I) derived from campholenic aldehyde, having a sandalwood-based fragrance note and improved acid stability. Furthermore, the present invention also relates to perfume compositions comprising one or more compounds of the present invention. Moreover, the present invention relates to the use of these compounds or perfume compositions as flavor enhancers or for improving the odor fixation of perfume compounds or perfume compositions and for the preparation of perfumed products. In addition, the present invention also relates to the use of the compounds or compositions for the preparation of perfumed products and to the perfumed products themselves.

Description

Technical Field

[0001] The present invention belongs to the field of fragrances and relates to novel fragrance compounds according to the general formula (I), which are derived from camphorenal and have a sandalwood-based fragrance and improved stability against acidic conditions. Furthermore, the present invention relates to fragrance compositions comprising one or more compounds of the present invention. Furthermore, the present invention relates to the use of these compounds or fragrance compositions as flavor enhancers, or for improving the aroma-fixing properties of fragrance compounds or fragrance compositions, and for preparing fragranced products. Furthermore, the present invention also relates to the use of these compounds or compositions for preparing fragranced products and the fragranced products themselves.

[0002] Background Art

[0003] Sandalwood is one of the oldest known and still most popular fragrance materials used in the perfumery industry. Originally produced in India, Ceylon, and Indonesia, it is extracted from the Santalum album tree. To meet high demand and given the worldwide dwindling availability of natural sources of sandalwood oil (Santalum album), a large number of synthetic fragrances with comparable odor characteristics have been produced in recent years.

[0004] Typically, α-camphorenal (2,2,3-trimethyl-3-cyclopentenal, C 10 H 16 O) is used as a starting material for these so-called "camphorene sandalwood" aroma chemicals.

[0005] For example, DE 3441902 C1 discloses β,γ-unsaturated 2,2,3-trimethylcyclopent-3-enyl derivatives and their use as flavor enhancers, particularly in combination with corresponding α,β-unsaturated alcohols. The derivatives are obtained by reducing the aldol condensation products of borneol and aliphatic aldehydes with sodium borohydride. These compounds have been found to exhibit woody, animalic, and soft fruity aromas.

[0006] It has further been found that the sandalwood odor is sensitive to slight structural changes and that the toughness of the perfume material can be increased, for example, by cyclopropanation.

[0007] For example, EP 0801049 B1 describes novel odorants derived from camphorenal, which contain at least one cyclopropane ring and a saturated or unsaturated side chain containing a double bond in position α, β or β, γ, respectively. The molecules obtained therein exhibit various woody odor aspects, most of them emitting a sandalwood odor, but some also exhibit woody / amber tones depending on cyclopropanation. It has further been found that [1-methyl-2-[(1,2,2-trimethyl-3-bicyclo[3.1.0]hexyl)methyl]cyclopropyl]methanol (also known as Givaudan) and in particular one specific diastereomer thereof, has a natural, strong and long-lasting sandalwood scent.

[0008] WO 2017 / 024126 A1 relates to a method for preparing a flavoring ingredient or fragrance ingredient by cyclopropanation of a substituted olefin using dihalomethane, and discusses the flavoring material [1-methyl-2-[(1,2,2-trimethyl-3-bicyclo[3.1.0]hexyl)methyl]cyclopropyl]methanol ( Givaudan).

[0009] However, there is currently still a high demand for synthetic substances that smell similar to sandalwood, and in addition, new fragrance compounds with comparable secondary olfactory properties (such as higher tenacity, low odour threshold, higher impact, i.e. odour intensity and longevity) and sufficient chemical stability (preferably chemical stability that is superior to the properties of natural sandalwood oil) are extremely popular.

[0010] In particular, sufficient chemical stability is required to ensure the stability of the fragrance materials in the product formulations and thereby the stability of the fragranced products themselves and, in turn, to ensure a high product quality with a consistent odor (i.e., high odor stability). Degradation of the fragrance materials may result in undesirable changes in fragrance note, color, etc. It is further known that certain fragrance materials are unstable over the entire pH range (such as in an acidic environment), making it difficult to incorporate certain fragrances into acidic formulations (such as toilet cleaners), limiting the applicability of these fragrance materials. Not only may it be challenging to incorporate these fragrance compounds into acidic product formulations, but also to use them as odor enhancers or in fragrance compositions, since the surface of human skin exhibits an acidic pH value of less than 5 on average. Therefore, the fragrance materials should not react with the skin or should not degrade and thereby result in changes in, among other things, the olfactory properties and secondary properties of the fragrance material.

[0011] However, it was found that (Givaudan) Chemically unstable under acidic conditions.

[0012] Therefore, the main object of the present invention is to provide novel sandalwood fragrance compounds which exhibit high chemical stability, particularly in acidic conditions, while showing enhanced olfactory properties very similar to the odor characteristics of natural sandalwood oil and at the same time showing improved fixative / toughness.

[0013] It has now surprisingly been found that new α-camphorenal-based compounds containing at least one cyclopropane substituent according to general formula (I) have a distinct natural, balanced and strong sandalwood oil odor, as well as high chemical stability and enhanced toughness in acidic environments, thereby providing excellent fragrance materials suitable for a wide range of applications. Summary of the Invention

[0014] In a first aspect, the present invention relates to a compound of formula (I):

[0015]

[0016] in

[0017] R represents H or an alkyl group, preferably, R represents H or a methyl group;

[0018] wherein at the dotted positions there is independently a single bond, a C=C double bond, or a cyclopropane ring; and

[0019] wherein the compound comprises at least one cyclopropane ring;

[0020] or a mixture of the above compounds;

[0021] or a stereoisomer of the above-mentioned compound or a mixture of these stereoisomers.

[0022] In a second aspect, the present invention relates to a fragrance composition comprising at least one compound according to the invention and at least one further fragrance material.

[0023] In a third aspect, the present invention relates to the use of a compound according to the invention or a fragrance composition comprising a compound according to the invention as a odorant or fragrance compound, or for improving the aroma fixing properties of a fragrance compound or a composition comprising a fragrance compound, or for preparing a perfumed product.

[0024] In another aspect, the present invention relates to a perfumed product comprising a compound according to the invention or a perfume composition comprising a compound according to the invention.

[0025] In another aspect, the present invention relates to a perfumed product comprising an effective amount of a compound according to the invention or a perfume composition comprising a compound according to the invention and a carrier or base.

[0026] Finally, the present invention relates to a perfumed product as defined comprising a compound according to the invention or a perfumery composition comprising a compound according to the invention, wherein the perfumed product is a fragrance oil, a fragrance base, a personal hygiene formulation, a cleanser or an air freshener.

[0027] The inventors have now determined that novel cyclopropanated compounds according to general formula (I) comprising at least one cyclopropane functionalization, and more particularly preferably comprising one or two cyclopropane functionalizations, have a distinct sandalwood-like odor with woody, green, floral and fruity notes, a very low odor threshold and high tenacity. Furthermore, the compounds according to the invention exhibit improved chemical stability under acidic conditions (and elevated temperatures), allowing the provision of highly effective fragrance materials or fragrance components suitable for various applications, in particular as fragrance ingredients for incorporation into acidic formulations. BRIEF DESCRIPTION OF THE DRAWINGS

[0028] Figure 1 : The compound of the present invention of general formula (I) is mixed with commercially available [1-methyl-2-[(1,2,2-trimethyl-3-bicyclo[3.1.0]hexyl)methyl]cyclopropyl]methanol (also known as Givaudan) in acidic conditions. DETAILED DESCRIPTION

[0029] According to the present invention, the above objects are achieved by compounds of general formula (I):

[0030]

[0031] in

[0032] R represents a hydrogen atom (H) or an alkyl group, preferably, R represents H or a methyl group (CH3);

[0033] wherein at the dotted positions there is independently a single bond, a C=C double bond, or a cyclopropane ring; and

[0034] wherein the compound comprises at least one cyclopropane ring;

[0035] or a mixture of the above compounds;

[0036] or a stereoisomer of the above-mentioned compound or a mixture of these stereoisomers.

[0037] The compounds of general formula (I) have an outstanding, balanced, and unique odor profile, very similar to the odor profile of natural sandalwood oil, which has woody, floral, green, and fruity notes and a remarkable toughness. Fruity and green aspects are not observed in the sandalwood fragrances of the prior art, resulting in a more complex and natural odor profile. It should be noted that the odor profile of natural sandalwood oil is also the result of many different odor notes, which are reminiscent of santalol, cedar oil, or guaiac oil, or sweet, balsamic, slightly ambery, spicy, or animalic notes, or even milky notes reminiscent of fresh boiled milk. However, commercially available sandalwood fragrances are generally described as having a rather deep and warm woody aroma with soft, creamy, and sweet notes, and are not as complex as natural sandalwood oil. None of the currently available synthetic fragrance materials from the Santalaceae family exhibit the same fresh nuances as those found for the substances according to the present invention. Based on the additional fruity and green nuances, the compounds developed herein are suitable for use as alternative fragrance materials with enhanced secondary properties and an enhanced and complex, balanced and thus more natural odor profile, adding green and fruity notes, which can be advantageously incorporated into a wide range of formulations to form a fresher and more vibrant fragrance. Thus, the present invention provides green and fruity notes and woody sandalwood, which are unique and not observed before or until now.

[0038] Furthermore, the compounds described herein have a high olfactory intensity even when used in low concentrations. Furthermore, the compounds according to the invention impress with their exceptional chemical stability, especially under acidic conditions (and elevated temperatures), and their high toughness. Consequently, these compounds are highly suitable as fragrances or in fragrance mixtures, as well as for use in formulations containing these fragrances or fragrance mixtures.

[0039] Surprisingly, it was found that the position of the functionalization within the butyl chain has a significant influence on the chemical stability of the product. The best stability and simultaneously the best olfactory properties (toughness, intensity, threshold) were found in substances in which the cyclopropane functionalization was located at the position indicated in general formula (I).

[0040] Thus, the butyl chain C1-C4 in the general formula (I) is defined as a four-carbon chain. In the general formula (I), the butyl chain is an n-butyl chain -CH2-CH2-CH2-CH2-, which is connected to the cyclopentane ring at one of its two terminal carbon atoms and to a hydroxyl group (-OH group) at the other terminal carbon atom (i.e., the carbon atom labeled C1).

[0041] In the general formula (I), R represents H or an alkyl group.

[0042] Preferably, the alkyl group is selected from the group consisting of a methyl group or a higher linear or branched alkyl group (such as an ethyl, propyl, n-butyl, or isobutyl group). More preferably, the alkyl group is an H or methyl group, as these result in compounds having a more natural and intense sandalwood aroma, as well as enhanced intensity and chemical stability. These compounds exhibit improved chemical stability and the most balanced and natural sandalwood-like odor characteristics with a green and fruity aroma.

[0043] Thus, in a preferred variant, the compound of general formula (I) comprises a methyl group attached as substituent R at position C2 to the butyl chain C1-C4.

[0044] It was further surprisingly found that these compounds exhibit a natural sandalwood-like odor and are chemically stable in acidic environments over a wide temperature range, particularly around room temperature (RTP).

[0045] However, the best combination of olfactory properties (odor characteristics, fragrance persistence and intensity / odor detection threshold) and chemical stability is achieved for the embodiment of formula (I), wherein R represents a hydrogen residue (H). Due to the exceptionally low threshold, exceptionally efficient fragrance materials can be provided based on the present invention.

[0046] Thus, in yet another even preferred variant, the compound of general formula (I) comprises a hydrogen residue attached as substituent R to the butyl chain C1-C4 at position C2.

[0047] Regardless of the above situation (i.e., R), at the dotted positions in the butyl chain C1-C4 and / or the cyclopentane ring in general formula (I), a C-C single bond, a C=C double bond, or a cyclopropane ring is present independently of each other. In the structural formula, the dotted lines are the most concise way to express these options. The meaning is also obvious to those skilled in the art, and their embodiments can be identified from the examples.

[0048] However, the compounds of general formula (I) contain at least one cyclopropane ring, resulting in enhanced toughness and a more pronounced sandalwood-like odor profile with fruity and green notes, as well as high chemical stability under acidic conditions.

[0049] Preferably, however, the compound of general formula (I) comprises two cyclopropane rings at two positions as indicated by the dotted lines, i.e. the two positions indicated by the dotted lines may represent cyclopropane functionalization, allowing to increase toughness and intensity while ensuring an enhanced odor profile and fresh fragrance.

[0050] Therefore, in a preferred variant, the present invention also relates to a compound according to the first aspect and more particularly according to the general formula (II):

[0051]

[0052] in

[0053] R represents H or an alkyl group, preferably, R represents H or a methyl group;

[0054] or a mixture of the above compounds;

[0055] or a stereoisomer of the above-mentioned compound or a mixture of these stereoisomers.

[0056] Thus, the substituent R has the functionality indicated above. However, the best olfactory results and stability are achieved for compounds in which R represents H or a methyl group. It has further been found that R should preferably represent a hydrogen atom, thereby obtaining an odor profile more similar to sandalwood with fresh green and fruity notes. Therefore, another particularly preferred embodiment of the present invention relates to compounds of formula (I) in which R represents a hydrogen atom.

[0057] It was found that compounds exhibiting two cyclopropane functional groups exhibited very high chemical stability in acidic environments, as well as excellent odor detection thresholds (hereinafter abbreviated as "ODT" values). Furthermore, the inventors were able to determine that these molecules exhibited a predominantly sandalwood, woody, green, floral, fruity, and creamy odor profile, as well as a strong, robust flavor profile, and exhibited improved toughness. Therefore, a particularly preferred embodiment of the present invention describes a compound of formula (II) wherein the molecule is dicyclopropanated, i.e., wherein cyclopropane functionalization occurs at the dotted positions within the cyclopentane ring and the butyl chain C1 to C4 of formula (I).

[0058] In another preferred variant, the compound of general formula (I) is monocyclopropanated, i.e., the compound according to general formula (I) contains only one cyclopropane ring at one of the dashed positions (i.e., either distally within the bulky cyclopentane moiety or in a proximal position within the C1-C4 butyl chain of the molecule). In these cases, at the other dashed positions, which therefore do not represent cyclopropanation, a C-C single bond or a C=C double bond, respectively, is present.

[0059] In a preferred variant, however, the monocyclopropanated compounds according to the invention contain a C═C double bond at the position indicated by the other dashed line in the molecule.

[0060] Therefore, in a preferred variant, the present invention relates to compounds according to general formula (I) wherein a C=C double bond is present at the dotted position within the C1-C4 butyl chain and a cyclopropane ring is present at the dotted position within the cyclopentane moiety.

[0061] Therefore, in a preferred variant of the invention, a compound according to the first aspect and more particularly according to the general formula (III) is described:

[0062]

[0063] in

[0064] R represents H or an alkyl group, preferably, R represents H or a methyl group;

[0065] or a mixture of the above compounds;

[0066] or a stereoisomer of the above-mentioned compound or a mixture of these stereoisomers.

[0067] Thus, the substituent R has the functionality indicated above. However, the best olfactory results and stability are achieved when R represents H or a methyl group, with R=H being preferred. In compounds according to formula (III) (wherein R represents a hydrogen residue), the resulting odor profile is more intense and exhibits fresher green and fruity notes, resulting in a more complex and pleasant fragrance. In addition, lower ODT values ​​are observed for these compounds, allowing for the realization of more efficient fragrance materials.

[0068] Furthermore, it was found that these compounds have odor characteristics similar to sandalwood, woody, green, and fruity aromas, as well as high odor intensity and tenacity, while showing high chemical stability under acidic conditions.

[0069] In an alternative variant of the invention, the compound of general formula (I) comprises a cyclopropane ring at the dotted position within the C1-C4 butyl chain and a C=C double bond at the dotted position within the cyclopentane moiety.

[0070] Therefore, an alternative variant of the invention relates to a compound according to the first aspect and more particularly according to general formula (IV):

[0071]

[0072] in

[0073] R represents H or an alkyl group, preferably, R represents H or a methyl group;

[0074] or a mixture of the above compounds;

[0075] or a stereoisomer of the above-mentioned compound or a mixture of these stereoisomers.

[0076] Thus, the substituent R has the functionality indicated above. However, the best olfactory results and stability are obtained when R represents H or a methyl group. Compared to compounds of formula (III), for compounds of formula (IV), the best primary and secondary olfactory properties are observed when R represents a hydrogen residue.

[0077] Furthermore, in an acidic environment, these compounds were found to display excellent primary and secondary aroma properties in terms of olfactory characteristics and chemical stability.

[0078] Therefore, in a preferred variant, the compound of general formula (I) comprises at least two functional groups selected from the group consisting of:

[0079] (a) Cyclopropane ring and

[0080] (b) a double bond,

[0081] The compound in turn comprises at least one cyclopropane function according to formula (II), (III) or (IV), respectively.

[0082] An alternative variant of the invention relates to monofunctionalized compounds according to general formula (I), such as compounds according to general formula (V):

[0083]

[0084] in

[0085] R represents H or an alkyl group, preferably, R represents H or a methyl group;

[0086] or a mixture of the above compounds;

[0087] or a stereoisomer of the above-mentioned compound or a mixture of these stereoisomers.

[0088] Thus, the substituent R has the functionality indicated above. However, the best olfactory results and stability are obtained when R represents H or a methyl group, and even more preferably H. Compared to the compounds of formulae (III) and (IV), for the compounds of formula (V), the best primary and secondary olfactory properties are observed if R represents a hydrogen residue.

[0089] Furthermore, it was found that the monofunctionalized compounds showing at least one cyclopropane functionality exhibit remarkable olfactory properties and secondary properties.The compounds according to formula (V) above exhibit a strong odor that can be described as cedarwood, sandalwood, creamy.

[0090] In another alternative embodiment of the invention, the monocyclopropanated compounds exhibit cyclopropane functionality within the bulky cyclopentane moiety, likewise showing excellent perfuming properties.

[0091] It is known that camphorenal may contain chiral centers and, depending on the specific isomerism of the α-pinene used as the starting material for its preparation, may exist as an isomeric pure form or as any mixture of its stereoisomers, in particular enantiomers. This means that compounds derived from camphorenal may also exist in different stereoisomeric forms. Therefore, whenever a compound of formula (I) is mentioned in this specification, this is considered to refer to all stereoisomers, in particular all enantiomers, and has nothing to do with isomeric pure stereoisomers or mixtures of any of their stereoisomers. For economic reasons, it is preferred to use compounds that are mixtures of their stereoisomers, in particular mixtures of their enantiomers. The same is true for monofunctionalized compounds of formula (II), (III) and (IV) and formula (V).

[0092] Thus, the compounds of general formula (I) and the compounds according to general formulae (II), (III) and (IV) as well as general formula (V) exist in the following forms:

[0093] (a) pure optically active enantiomers;

[0094] (b) a racemic mixture of enantiomers; or

[0095] (c) Optically active mixtures of various enantiomers.

[0096] Therefore, the present invention also discloses a mixture of any of the above-mentioned compounds and / or a mixture of any of the above-mentioned stereoisomers, as well as the use of such compounds and / or mixtures in the sense of the present application.

[0097] Moreover, in this context, the present invention also discloses single isomeric forms of compounds according to general formula (I) and more specifically general formula (II), (III), (IV) and / or (V). Single isomeric forms of compounds according to general formula (II) are exemplified below:

[0098]

[0099] The isomeric structure corresponding to the general formula (II).

[0100] Similarly, single isomeric structures of compounds of formula (I), (III) and (IV) as well as compound (V) can be derived.

[0101] In general, in the context of the present invention, the term "compound of formula (I)" means a single compound of formula (I) (and its isomeric forms) and all mixtures of the compound of formula (I) (and its isomeric forms) in any mixing ratio. That is, the statements about "compound of formula (I)" in the following description apply both to a single compound of formula (I), a single isomeric form, and to mixtures consisting of or comprising the compound of formula (I) and its isomeric forms in any mixing ratio. These definitions also apply to compounds of formula (II), (III) and / or (IV) and / or (V). Therefore, the present invention relates to single compounds according to the invention per se and mixtures of compounds according to the invention.

[0102] In addition, at the positions of chain branching, i.e., at the C atoms marked C2 and C3 in formulae (I) to (V), additional chiral centers may be present. Moreover, with reference to formula (I), and in particular to formula (III) or (IV) and the C=C double bonds contained therein, the compounds may optionally exist in the form of geometric isomers (i.e., Z configuration and / or E configuration).

[0103] The compounds of general formula (I) surprisingly possess a strong and balanced odor profile (primary profile), in particular a strong and balanced sandalwood odor, which closely resembles the complexity of the natural woody odor profile of sandalwood with fresh green and fruity notes, while at the same time exhibiting high chemical stability under acidic conditions. In particular, the new alcohols of general formula (I) and more specifically the alcohols of general formulae (II), (III) and (IV) and the monofunctionalized compounds of general formula (V) exhibit a strong and natural sandalwood-based woody, green and fruity odor profile, combined with surprisingly increased toughness.

[0104] In particular, compounds of general formula (II) exhibit a natural and intense sandalwood fragrance with a fresh green and fruity aroma. Furthermore, these compounds exhibit extremely high intensity and high chemical stability in acidic environments. Therefore, compounds of general formula (II) are particularly useful as fragrance compounds and for the preparation of flavoring products, especially in acidic formulations.

[0105] Among the novel compounds of general formula (I), those having cyclopropane functionalization at both positions indicated by the dotted line (i.e. compounds according to general formula (II)) have particularly strong sandalwood-based notes, as well as low ODT values, high toughness and high chemical stability in acidic conditions, which are superior to commercially available cyclopropanated sandalwood-type fragrance materials, such as (Givaudan). These compounds therefore exhibit the superior primary and secondary properties required to provide excellent fragrance materials. This fact may seem surprising in view of the similarities between the molecular structures of the novel compounds of general formula (I) and particularly general formula (II) and those of the prior art, but the odor of a compound is highly sensitive to structural changes.

[0106] Therefore, within the scope of the present invention as indicated above, these dicyclopropanated compounds are particularly preferred.

[0107] The dicyclopropanated compounds according to formula (I) and more particularly according to formula (II) wherein R represents a hydrogen atom (compound 3b) or a methyl group (compound 3a) are reacted with A direct comparison of the corresponding ODT values ​​of ANTI-SANDALWOOD (Givaudan) shows that the compounds of the present invention exhibit comparable or even better thresholds than the commercially available sandalwood fragrance (see Table 1).

[0108] The odour detection threshold is defined as the lowest concentration of a certain odour-emitting compound (gaseous and sensory active substances) which is perceptible and thus clearly distinguishable from a blank reference under standard conditions. In general, lower ODT values ​​are preferred, since smaller amounts of the corresponding fragrance compound are required to achieve a strong odour impression, so that smaller amounts can be used overall for perfumery. However, since this threshold depends on various factors such as concentration, solubility, partition coefficient between air and olfactory active substances, vapour pressure, etc., it is difficult to predict the ODT of reference substances (i.e. fragrance materials). The ODT is measured according to DIN standard EN 13725 using an olfactometer TO8 and a panel of at least four experts.

[0109] Surprisingly, it was found that compounds of general formula (I), and more particularly general formula (II), emit a natural, complex sandalwood-like odor of high intensity / strength. In view of the superior intensity, compounds according to general formula (II) in which R represents a hydrogen atom (compound 3b) are particularly preferred.

[0110] Commercially available dicyclopropanated sandalwood fragrance material Compared to the odorless, woody, and sandalwood-like fragrances of Givaudan, compound 3b exhibits a substantially lower threshold of approximately 6.5-fold, distinguishing it by its high intensity. Consequently, a relatively low amount of the compound is required to achieve a relatively intense, natural woody, sandalwood-like fragrance. Consequently, the compounds of the present invention are more effective as fragrance materials.

[0111] Table 1: Compounds of the present invention (compounds 3a and 3b) according to general formula (I) and commercially available Comparison of ODT values ​​of (Givaudan)

[0112]

[0113] *:ODT: Odor Detection Threshold

[0114] Therefore, according to Table 1, compound 3b according to general formula (II) herein is the most preferred compound in view of its extraordinary ODT value and high toughness.

[0115] The compounds of general formula (I) and general formulae (II) to (V) according to the present invention can be used as individual substances or in a mixture with at least one other known flavoring substance selected from a wide range of natural and synthetic substances that can be used in a large number of flavoring mixtures and / or in admixture with one or more ingredients or excipients (such as carrier materials and other auxiliaries commonly used in the art) that are conventionally used in combination with flavor enhancers in flavoring compositions.

[0116] The olfactory properties of the novel compounds according to formula (I), and more particularly according to formulas (II), (III) and (IV), and the monofunctionalized compounds of formula (V) are compatible with a variety of natural or synthetic fragrance substances. Therefore, in particular in view of their high toughness and low threshold, they can be advantageously used to prepare fragrance compositions comprising at least one compound according to the present invention and at least one other fragrance substance to produce a long-lasting and strong fragrance composition with an interesting but naturally novel and original fragrance note. In particular, the compounds described herein can be advantageously used to add fresher fragrance notes with green and fruity aromas to various formulations, resulting in a fresher, more vibrant and more balanced odor profile compared to commercial sandalwood-based products that are quite warm and heavy. In addition, the compounds of the present invention, due to their enhanced chemical stability under acidic conditions, allow for formulations containing natural acidic components such as essential oils (such as citrus oils with a pH of about 5 to 5.8).

[0117] Thus, in a second aspect, the present invention relates to a fragrance composition comprising at least one compound according to the invention and at least one further fragrance material.

[0118] The fragrance substances specified below can be used as individual substances or in mixtures with at least one, two, three or even more fragrance substances, in a large number of fragrance mixtures selected from a wide range of natural and synthetic substances.

[0119] For example, in "S. Arctander, Perfume and Flavor Materials, Volumes I and II, Montclair, New Jersey 1969, privately published" and / or "H. Surburg, J. Panten, Common Fragrance and Flavor Materials, 6th edition, Wiley-VCH, Weinheim 2016", there are lists of flavoring substances that are advantageously suitable for combination. The following list includes examples of known odorant substances that are advantageously suitable for combination with the compounds according to the invention and their mixtures:

[0120] Extracts of natural raw materials, such as essential oils, concretes, absolutes, resins, resinoids, balms, tinctures, such as, for example:

[0121] Ambergris tincture, amyris oil, angelica seed oil, angelica root oil, fennel oil, valerian oil, basil oil, moss absolute, bay oil, mugwort oil, benzoin resin, bergamot oil, beeswax absolute, birch tar, bitter almond oil, savory oil, basil leaf oil, cabreuva oil, cade oil, calamus oil, camphor oil, cananga oil, cardamom oil, cascarilla oil, cassia oil, cassie absolute, castoreum absolute, cedar leaf oil, cedarwood oil, labdanum oil, citronella oil, lemon oil, copaiba balsam, copal balsam oil, coriander oil, costus root oil oil), cumin oil, cedarwood oil, davana oil, dill weed oil, dill seed oil, brouts absolute, oakmoss absolute, elemi oil), tarragon oil, lemon eucalyptus oil, eucalyptus oil, fennel oil, pine needle oil, galbanum oil, galbanum resin, geranium oil oil), grapefruit oil, guaiac wood oil, gurjun balsam, gurjun balsam oil, helichrysum absolute, helichrysum oil, ginger oil, orris root absolute, orris 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 lemon oil, pressed lemon oil, linaloe oil, Litsea cubeba cubeba oil, bay leaf oil, mace oil, marjoram oil, mandarin oil, massoia bark oil, mimosa absolute, ambrette oil, musk tincture, muscatel sage oil, nutmeg oil, myrrh absolute, myrrh oil, myrtle oil, clove leaf oil, clove flower oil, neroli oil, frankincense absolute, frankincense oil, opoponax oil, neroli absolute, orange oil, origanum oil, palmarosa oil, patchouli oil, perilla seed oil, Peru balsam oil, parsley leaf oil, parsley seed oil, petitgrain oil, peppermint oil, peppermint oil, pimento oil, pine oil, pennyroyal oil, rose absolute, rosewood oil, rose oil, rosemary oil, Dalmatian sage oil, Spanish sage oil, sandalwood oil, celery seed oil, spike lavender lavender oil, staranise oil, styrax oil, marigold oil, fir needle oil, tea tree oil, turpentine oil, thyme oil, tolu balsam, tonka absolute, tuberose absolute, vanilla extract, violet leaf absolute, verbena oil, vetiver oil, juniper berry oil, cognac oil, wormwood oil, wintergreen oil, ylang ylang oil, hyssop oil, civet absolute, cinnamon leaf oil, camphor bark oil, and fractions thereof or components isolated therefrom;

[0122] Individual flavor substances from the group comprising hydrocarbons, such as, for example: 3-carene, α-pinene, β-pinene, α-terpene, γ-terpene, p-cymene, bisabolene, camphene, caryophyllene, cedrene, farnesene, limonene, longifolene, myrcene, ocimene, valenciaene, (E,Z)-1,3,5-undecatriene, styrene, diphenylmethane;

[0123] Aliphatic alcohols, such as, for example: hexanol, octanol, 3-octanol, 2,6-dimethylheptanol, 2-methyl-2-heptanol, 2-methyl-2-octanol, (E)-2-hexenol, a mixture of (E)- and (Z)-3-hexenol, 1-octen-3-ol, a 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-decenyl-5-ol;

[0124] Aliphatic aldehydes and their acetals, such as, for example: hexanal, heptanal, octanal, nonanal, decanal, undecanal, dodecanal, tridecanal, 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, heptaldehyde diethyl acetal, 1,1-dimethoxy-2,2,5-trimethyl-4-hexene, citronellyloxyacetaldehyde, 1-(1-methoxypropoxy)-(E / Z)-3-hexene;

[0125] Aliphatic ketones and their oximes, such as, for example: 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;

[0126] Aliphatic sulfur-containing compounds, such as, for example: 3-methylthiohexanol, 3-methylthiohexyl acetate, 3-mercaptohexanol, 3-mercaptohexyl acetate, 3-mercaptohexylbutyrate, 3-acetylthiohexyl acetate, 1-menthene-8-thiol;

[0127] Aliphatic nitriles, such as, for example: 2-nonenoic acid nitrile, 2-undecenoic acid nitrile, 2-tridecenoic acid nitrile, 3,12-tridecadienoic acid nitrile, 3,7-dimethyl-2,6-octadienoic acid nitrile, 3,7-dimethyl-6-octenoic acid nitrile;

[0128] Esters of aliphatic carboxylic acids, such as, for example: (E)- and (Z)-3-hexenylcarboxylate, ethyl acetoacetate, isoamyl acetate, hexyl 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-isobutyl ester, hexyl crotonate, ethyl isovalerate, ethyl 2-methylpentanoate, ethyl hexanoate, allyl hexanoate, ethyl heptanoate, allyl heptanoate, ethyl octanoate, ethyl (E,Z)-2,4-decadienoate, methyl 2-octanoate, methyl 2-nonanoate, allyl 2-isopentyloxyacetate, methyl 3,7-dimethyl-2,6-octadienoate, 4-methyl-2-pentyl-crotonate;

[0129] Acyclic terpene alcohols such as, for example: citronellol, geraniol, nerol, linalool, lavandinol, 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-2-ol, 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, and their formates, acetates, propionates, isobutyrates, butyrates, isovalerates, valerates, hexanoates, crotonates, tiglinates or 3-methyl-2-butenoates;

[0130] Acyclic terpene aldehydes and ketones, such as, for example: geranial, neral, citronellal, 7-hydroxy-3,7-dimethyloctanal, 7-methoxy-3,7-dimethyloctanal, 2,6,10-trimethyl-9-undecenal, geranylacetone, and also the dimethyl acetal and diethyl acetal of geranial, neral, 7-hydroxy-3,7-dimethyloctanal;

[0131] Cyclic terpene alcohols, such as, for example: menthol, isomenthol, α-terpineol, terpinenol-4, menthan-8-ol, menthan-1-ol, menthan-7-ol, borneol, isoborneol, linalool oxide, nofol, cedarol, ambroxol, vetivol, guaiacol, and their formates, acetates, propionates, isobutyrates, butyrates, isovalerates, valerates, hexanoates, crotonates, tiglic acid esters or 3-methyl-2-butenoates;

[0132] Cyclic terpene aldehydes and ketones, such as, for example: menthone, isomenthone, 8-mercaptomenthan-3-one, carvone, camphor, fenchone, α-ionone, β-ionone, α-n-methylionone, β-n-methylionone, α-isomethylionone, β-isomethylionone, α-irone, α-damascenone, β-damascenone, β-damascenone, δ-damascenone, γ-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-naphthone-8(5H)-one, 2-methyl-4-(2,6,6-trimethyl-1-cyclohexen-1-yl)-2-butenal, nootkatone, dihydronootkatone, 4,6,8-megastigmatrien-3-one, α-citronellal, β-citronellal, acetylated cedarwood oil (methyl cedryl ketone);

[0133] Cyclic alcohols, such as, for example: 4-tert-butylcyclohexanol, 3,3,5-trimethylcyclohexanol, 3-isocamphylcyclohexanol, 2,6,9-trimethyl-Z2,Z5,E9-cyclododecatrien-1-ol, 2-isobutyl-4-methyltetrahydro-2H-pyran-4-ol;

[0134] Alicyclic alcohols, such as, for example: α-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, 2-ethyl-4-(2,2,3-trimethyl-3-cyclopent-1-yl)-2-buten-1-ol , 3-methyl-5-(2,2,3-trimethyl-3-cyclopentanone-1-yl)-pentane-2-ol, 3-methyl-5-(2,2,3-trimethyl-3-cyclopentan-1-yl)-4-penten-2-ol, 3,3-dimethyl-5-(2,2,3-trimethyl-3-cyclopentan-1-yl)-4-penten-2-ol, 1-(2,2,6-trimethylcyclohexyl)pentane-3-ol, 1-(2,2,6-trimethylcyclohexyl)hexane-3-ol;

[0135] Cyclic and alicyclic ethers, such as, for example: cineole, cedryl methyl ether, cyclododecyl methyl ether, 1,1-dimethoxycyclododecane, (ethoxymethoxy)cyclododecane, α-cedrene epoxide, 3a,6,6,9a-tetramethyldodecahydronaphtho[2,1-b]furan, 3a-ethyl-6,6,9a-trimethyldodecahydronaphtho[2,1-b]furan, 1,5,9-trimethyl-13-oxabicyclo[10.1.0]trideca-4,8-diene, rose oxide, 2-(2,4-dimethyl-3-cyclohexen-1-yl)-5-methyl-5-(1-methylpropyl)-1,3-dioxane;

[0136] Cyclic ketones and macrocyclic ketones, such as, for example: 4-tert-butylcyclohexanone, 2,2,5-trimethyl-5-pentylcyclopentanone, 2-heptylcyclopentanone, 2-pentylcyclopentanone, 2-hydroxy-3-methyl-2-cyclopenten-1-one, 3-methyl-cis-2-penten-1-yl-2-cyclopenten-1-one, 3-methyl-2-pentyl-2-cyclopenten-1-one, 3-methyl-4-cyclopentadecenone, 3-methyl- -5-cyclopentadecenone, 3-methylcyclopentadecenone, 4-(1-ethoxyvinyl)-3,3,5,5-tetramethylcyclohexanone, 4-tert-pentylcyclohexanone, 5-cyclohexadecene-1-one, 6,7-dihydro-1,1,2,3,3-pentamethyl-4(5H)-indanone, 8-cyclohexadecene-1-one, 9-cycloheptadecene-1-one, cyclopentadecanone, cyclohexadecanone;

[0137] Alicyclic aldehydes, such as, for example: 2,4-dimethyl-3-cyclohexenecarboxaldehyde, 2-methyl-4-(2,2,6-trimethyl-cyclohexen-1-yl)-2-butenal, 4-(4-hydroxy-4-methylpentyl)-3-cyclohexenecarboxaldehyde, 4-(4-methyl-3-penten-1-yl)-3-cyclohexenecarboxaldehyde;

[0138] Cycloaliphatic ketones, such as, for example: 1-(3,3-dimethyl-cyclohexyl)-4-penten-1-one, 2,2-dimethyl-1-(2,4-dimethyl-3-cyclohexen-1-yl)-1-propanone, 1-(5,5-dimethyl-1-cyclohexen-1-yl)-4-penten-1-one, 2,3,8,8-tetramethyl-1,2,3,4,5,6,7,8-octahydro-2-naphthylmethyl ketone, methyl-2,6,10-trimethyl-2,5,9-cyclododecantrienyl ketone, tert-butyl-(2,4-dimethyl-3-cyclohexen-1-yl)ketone;

[0139] Cyclic alcohol esters such as, for example: 2-tert-butylcyclohexyl acetate, 4-tert-butylcyclohexyl acetate, 2-tert-pentylcyclohexyl acetate, 4-tert-pentylcyclohexyl acetate, 3,3,5-trimethylcyclohexyl acetate, decahydro-2-naphthalene acetate, 2-cyclopentylcyclopentyl crotonate, 3-pentyltetrahydro-2H-pyran-4-yl acetate, decahydro-2,5,5,8a-tetramethyl-2-naphthalene acetate, 4,7-methylene (Met esters of cycloaliphatic alcohols, such as, for example, 1-cyclohexylethyl crotonate;

[0140] Cycloaliphatic alcohol esters, such as, for example: allyl-3-cyclohexylpropionate, allyl cyclohexyloxyacetate, methyl cis- and trans-dihydrojasmonate, methyl cis- and trans-jasmonate, 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; aromatic aliphatic alcohols, such as, for example, benzyl alcohol, 1-phenylethanol, 2- Phenylethanol, 3-phenylpropanol, 2-phenylpropanol, 2-phenoxyethanol, 2,2-dimethyl-3-phenylpropanol, 2,2-dimethyl-3-(3-methylphenyl)propanol, 1,1-dimethyl-2-phenylethanol, 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;

[0141] Aromatic aliphatic alcohol esters and aliphatic carboxylic acid esters, such as, for example: benzyl acetate, benzyl propionate, benzyl isobutyrate, benzyl isovalerate, ethyl 2-phenylacetate, 2-phenylethyl propionate, 2-phenylethyl isobutyrate, 2-phenylethyl isovalerate, 1-phenylethyl acetate, α-trichloromethylbenzyl acetate, ethyl α,α-dimethylphenylacetate, α,α-dimethylphenyl-ethyl butyrate, cinnamyl acetate, 2-phenoxyethyl isobutyrate, 4-methoxybenzyl acetate;

[0142] Aromatic aliphatic ethers, such as, for example: 2-phenylethyl methyl ether, 2-phenylethyl isoamyl ether, 2-phenylethyl 1-ethoxyethyl ether, phenylacetaldehyde dimethyl acetal, phenylacetaldehyde diethyl acetal, hydratropaldehyde dimethyl acetal, phenylacetaldehyde glycerol acetal, 2,4,6-trimethyl-4-phenyl-1,3-dioxane, 4,4a,5,9b-tetrahydroindeno[1,2-d]-m-dioxin, 4,4a,5,9b-tetrahydro-2,4-dimethylindeno[1,2-d]-m-dioxin;

[0143] Aromatic and aromatic aliphatic aldehydes such as, for example: benzaldehyde, phenylacetaldehyde, 3-phenylpropanal, hydratropaldehyde, 4-methylbenzaldehyde, 4-methylphenylacetaldehyde, 3-(4-ethylphenyl)-2,2-dimethylpropanal, 2-methyl-3-(4-isopropylphenyl)propanal, 2-methyl-3-(4-tert-butylphenyl)propanal, 2-methyl-3-(4-isobutylphenyl)propanal, 3-(4 -tert-butylphenyl)propanal, cinnamaldehyde, α-butylcinnamaldehyde, α-amylcinnamaldehyde, α-hexylcinnamaldehyde, 3-methyl-5-phenylpentanal, 4-methoxybenzaldehyde, 4-hydroxy-3-methoxybenzaldehyde, 4-hydroxy-3-ethoxybenzaldehyde, 3,4-methylenedioxybenzaldehyde, 3,4-dimethoxybenzaldehyde, 2-methyl-3-(4-methoxyphenyl)propanal, 2-methyl-3-(4-methylenedioxyphenyl)propanal;

[0144] Aromatic and araliphatic ketones, such as, for example: acetophenone, 4-methylacetophenone, 4-methoxyacetophenone, 4-tert-butyl-2,6-dimethylacetophenone, 4-phenyl-2-butanone, 4-(4-hydroxyphenyl)-2-butanone, 1-(2-naphthyl)ethanone, 2-benzofuranone, (3-methyl-2-benzofuranyl)ethanone, benzophenone, 1,1,2,3,3,6-hexamethyl-5-indanylmethylketone, 6-tert-butyl-1,1-dimethyl-4-indanylmethylketone, 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-acetonapthone;

[0145] Aromatic and araliphatic carboxylic acids and esters thereof, such as, for example: benzoic acid, phenylacetic acid, methyl benzoate, ethyl benzoate, hexyl benzoate, benzyl benzoate, methyl phenylacetate, ethyl phenylacetate, geranyl phenylacetate, phenylethylphenyl acetate, methyl cinnamate, ethyl cinnamate, benzyl cinnamate, phenylethyl cinnamate, cinnamyl cinnamate, allylphenoxyacetate, methyl salicylate, isoamyl salicylate, hexyl salicylate, cyclohexyl salicylate, cis-3-hexenyl salicylate, benzyl salicylate, phenylethyl salicylate, methyl-2,4-dihydroxy-3,6-dimethylbenzoate, ethyl-3-phenyl glycidate, ethyl-3-methyl-3-phenyl glycidate;

[0146] Nitrogen-containing aromatic compounds such as, for example: 2,4,6-trinitro-1,3-dimethyl-5-tert-butylbenzene, 3,5-dinitro-2,6-dimethyl-4-tert-butylacetophenone, cinnamonitrile, 3-methyl-5-phenyl-2-pentenenitrile (2-pentenoic acidnitrile), 3-methyl-5-phenylpentanoic acidnitrile (5-phenylpentanoic acidnitrile), nitrile), methyl anthranilate, methyl-N-anthranilate, a Schiff base of methyl anthranilate and 7-hydroxy-3,7-dimethyloctanal, 2-methyl-3-(4-tert-butylphenyl)propanal or 2,4-dimethyl-3-cyclohexenecarboxaldehyde, 6-isopropylquinoline, 6-isobutylquinoline, 6-sec-butylquinoline, 2-(3-phenylpropyl)pyridine, indole, skatole, 2-methoxy-3-isopropylpyrazine, 2-isobutyl-3-methoxypyrazine;

[0147] Phenols, phenyl ethers and phenyl esters, such as, for example: estragole, anethole, eugenol, eugenyl methyl ether, isoeugenol, isoeugenyl methyl ether, thymol, carvacrol, diphenyl ether, β-naphthyl methyl ether, β-naphthyl ethyl ether, β-naphthyl isobutyl ether, 1,4-dimethoxybenzene, eugenyl acetate, 2-methoxy-4-methylphenol, 2-ethoxy-5-(1-propenyl)phenol, p-tolylphenyl acetate;

[0148] Heterocyclic compounds, such as, for example: 2,5-dimethyl-4-hydroxy-2H-furan-3-one, 2-ethyl-4-hydroxy-5-methyl-2H-furan-3-one, 3-hydroxy-2-methyl-4H-pyran-4-one, 2-ethyl-3-hydroxy-4H-pyran-4-one;

[0149] Lactones such as, for example: 1,4-octanolactone, 3-methyl-1,4-octanolactone, 1,4-nonanolactone, 1,4-decanolactone, 8-decenyl-1,4-lactone, 1,4-undecalactone, 1,4-dodecalactone, 1,5-decanolactone, 1,5-dodecalactone, 4-methyl-1,4-decanolactone, 1,15-pentadecalactone, cis- and trans-11-pentadecen-1,15-lactone, cis- and trans-11-pentadecen-1,15-lactone trans-12-pentadecen-1,15-lactone, 1,16-hexadecane lactone, 9-hexadecene-1,16-lactone, 10-oxa-1,16-hexadecane lactone, 11-oxa-1,16-hexadecane lactone, 12-oxa-1,16-hexadecane lactone, 1,12-dodecane dioic acid vinyl ester, 1,13-tridecane dioic acid vinyl ester, coumarin, 2,3-dihydrocoumarin, octahydrocoumarin;

[0150] and mixtures of the above substances.

[0151] In such fragrance compositions, the compounds according to the present invention exert a positive influence on the overall fragrance base by significantly enhancing the woody and sandalwood-like properties of the final composition with a fresh fragrance note, while at the same time providing good toughness, fixation, and longevity. Thus, the compounds according to the present invention described herein can be used as highly effective and stable fragrance compounds.

[0152] It goes without saying that it is preferred, although not absolutely necessary, that the fragrance composition according to the invention comprises a certain amount of a compound according to the invention, preferably according to general formula (II), which is olfactorily perceptible as a woody sandalwood odor note. However, due to the low ODT value, only a small amount of the compound according to the invention is required to obtain the desired odor profile.

[0153] Furthermore, due to their high chemical stability to acidic conditions, the compounds of the present invention can be incorporated as fragrance components into a variety of fragrance compositions regardless of the pH of the overall formulation.

[0154] In fragrance compositions, the compounds according to the invention are preferably used in an amount ranging from 0.0001 to 90% by weight, preferably from 0.01 to 70% by weight and particularly preferably from 0.1 to 50% by weight, relative to the total amount of the fragrance composition.

[0155] The fragrance compounds according to the invention and fragrance compositions comprising or containing at least one compound according to the invention can be used for perfuming applications in liquid form, either undiluted or diluted with a solvent. Suitable solvents for this purpose are, for example, ethanol, isopropanol, diethylene glycol monoethyl ether, glycerol, propylene glycol, 1,2-butylene glycol, dipropylene glycol, diethyl phthalate, triethyl citrate, isopropyl myristate, triacetin, vegetable oils, and the like.

[0156] Furthermore, the flavoring compounds according to the present invention or the flavoring compositions comprising or containing the compounds according to the present invention may be adsorbed on a carrier which ensures a fine distribution of the flavoring substances in the final product and a controlled release during use. Such carriers may be porous inorganic materials such as sodium sulfate, silica gel, zeolite, gypsum, clay, clay particles, aerated concrete, etc., or organic materials such as wood, cellulosic materials, sugars, dextrins (e.g. maltodextrin), or plastics such as PVC, polyvinyl acetate or polyurethane.

[0157] The fragrance compounds according to the present invention and the fragrance compositions comprising or containing the compounds indicated by formula (I) to (V) according to the present invention can also be microencapsulated, spray-dried, provided as inclusion complexes or as extruded products (i.e. products according to the present invention).

[0158] Alternatively, the properties of the fragrance compound or composition modified in this way can be further optimized with regard to a more targeted fragrance release by "coating" it with a suitable material, for which purpose waxy plastics such as, for example, polyvinyl alcohol are preferably used. The resulting product is then a product according to the invention.

[0159] The fragrance compounds according to the invention or the fragrance compositions according to the invention can be encapsulated, for example, by coacervation with the aid of capsule materials made, for example, of polyurethanes or soft gelatin.

[0160] Spray-dried fragrance formulations based on the fragrance compounds according to the invention and fragrance compositions comprising or containing the compounds according to the invention can be prepared, for example, by spray-drying emulsions or dispersions comprising or containing the fragrance compounds or compositions, wherein modified starches, proteins, dextrins and vegetable gums can be used as carriers. Inclusion complexes can be prepared, for example, by introducing a dispersion of the fragrance compound or composition with a cyclodextrin or urea derivative into a suitable solvent, such as water.

[0161] Extruded products may be produced by melting the fragrance compound or composition with a suitable waxy substance, optionally in a suitable solvent (eg isopropyl alcohol), extruding and subsequently solidifying.

[0162] Since the compounds described herein have a unique sandalwood aroma with green and fruity notes, combined with their superior secondary properties (such as low ODT value and high chemical stability) over the sandalwood fragrance materials known in the prior art, the compounds according to general formula (I) and preferably the compounds according to general formula (II), or fragrance compositions comprising or containing the compounds according to the present invention, enable balanced sandalwood notes to be obtained in the resulting perfumed formulations / products even at low addition rates of the (fragrance) compounds of the present invention, while ensuring enhanced fixative properties (toughness) and improved chemical stability in acidic environments / formulations.

[0163] In another aspect, the present invention thus relates to the use of a compound according to general formula (I) or a flavor composition comprising or containing a compound according to the invention as a high-potency odorant or flavor compound.The above remarks apply correspondingly to the preferred compounds and mixtures.

[0164] Due to their exceptional first and second olfactory properties (such as tenacity), low odor threshold and high chemical stability, the present invention also relates accordingly to the use of compounds according to general formula (I) or fragrance compositions comprising or containing at least one compound according to the invention for improving the aroma fixing properties of fragrance compounds, simultaneously using these compounds or compositions comprising or containing at least one compound according to the invention as fragrance substances and for preparing perfumed products. With regard to the preferred selection of the compounds and mixtures according to the invention, the above remarks naturally apply accordingly.

[0165] The present invention therefore relates to the use of the above-mentioned compounds and compositions for improving the fragrance fixing properties of fragrance compounds or for preparing perfumed products.

[0166] The compounds or compositions comprising (including) or containing the compounds according to the invention can be incorporated into perfumed or intended perfumed products, in particular formulations for personal hygiene, such as perfume oils, perfume bases, personal hygiene formulations, cleansers or air fresheners.

[0167] Therefore, in another aspect, the present invention also relates to a perfumed product comprising or containing a compound according to the invention and of formula (I) or a perfume composition comprising or containing at least one compound according to the invention.

[0168] According to a preferred variant, the perfuming product according to the invention comprising or containing a compound according to the invention or a perfume composition comprising or containing said compound is obtained by incorporating said compound or a composition comprising or containing said compound in pure form without solvent, as a solution or in a mixture with a solid or liquid carrier and optionally other auxiliaries and / or stabilizers to form a base formulation for personal hygiene (such as a cleanser, etc.).

[0169] The present invention therefore also provides a perfumed product comprising or containing an effective amount of a compound of formula (I) (or formula (II), (III) and / or (IV) and / or (V)), or a perfume composition comprising or containing at least one compound according to the invention, in combination with a carrier or base.

[0170] An organoleptically effective amount means that a portion of the substances of formula (I), formula (II), formula (III) and / or formula (IV) and the monofunctionalized compound of general formula (V), in particular the compound according to general formula (I), in the mixture is sufficient to emit a pleasant perceptible fragrance impression, in particular a woody odor impression similar to sandalwood. This perceptible olfactory impression is generally achieved when at least 0.001% by weight of the compounds of formula (I), formula (II), formula (III) and / or formula (IV) and / or formula (V) are present in the final preparation / formulation.

[0171] In addition to their strong organoleptic properties, the compounds of formula (I) described herein also possess additional favorable secondary properties, such as high stability under certain application conditions. This stability, particularly in acidic media, qualifies the compounds of the present invention for use and processing in a wide range of applications.

[0172] Perfuming products according to the invention are, for example, pure essences (perfume extracts), eau de parfum, eau de toilette, shaving lotions, colognes, pre-shave products, colognes and perfumed wet wipes, including products for perfuming acidic, alkaline and neutral cleaners (such as, for example, floor cleaners, window cleaners, dishwashing detergents, bathroom cleaners, stain remover pastes, solid and liquid toilet cleaners, powdered and foaming carpet cleaners), textile refreshers, ironing aids, liquid detergents, powdered detergents, laundry pretreaters (such as bleaches, soaking agents and stain removers), laundry rinse conditioners, laundry soaps, laundry tablets, disinfectants, surface disinfectants and air fresheners in liquid or gel form or those applied to a solid carrier, aerosol sprays, waxes and polishes (such as furniture polish, floor wax and shoe polish) and body care products (such as, for example, solid and liquid soaps, shower gels, shampoos, shaving soaps, shaving foams, bath oils), Oil-in-water, water-in-oil and water-in-oil-in-water cosmetic emulsions (such as, for example, skin creams and lotions, face creams and lotions, sunscreens and lotions, after-sun creams and lotions, hand creams and lotions, foot creams and lotions, depilatory creams and lotions, aftershave creams and lotions, self-tanning creams and lotions), hair care products (such as, for example, hair sprays, hair gels, strengthening shampoos, conditioners, permanent and semi-permanent hair dyes, hair styling agents (such as cold wave and straighteners), hair tonics, hair creams and lotions), deodorants and antiperspirants (such as, for example, underarm sprays, roll-ons, deodorant sticks, deodorant creams), decorative cosmetics (such as, for example, eye shadows, nail polishes, make-up products, lipsticks, mascaras) as well as candles, lamp oils, incense sticks, insecticides, insect repellents and fuels or oral and / or dental care products (such as toothpaste, tooth gel, tooth powder, mouthwash, chewing gum and other oral care products).

[0173] The product according to the invention may also be a semi-finished product comprising a compound of general formula (I) in an effective amount or a fragrance composition containing or comprising at least one compound according to the invention.

[0174] The percentage used of the compound of general formula (I) according to the present invention or the perfume composition containing or comprising at least one compound according to the present invention can change in a very wide range, from a few thousandths in mass market products (such as detergents) to a few percent in alcohol extracts in the manufacture of high-end perfumes. However, even a small amount of novel compounds or perfume compositions containing or comprising at least one compound according to the present invention provide a rich sandalwood or woody note for perfumed formulations / products. Preferably, the amount of the compound of general formula (I) according to the present invention or the perfume composition containing or comprising at least one compound according to the present invention is 0.0001% by weight to 90% by weight, preferably 0.01% by weight to 70% by weight and particularly preferably 0.1% by weight to 50% by weight, calculated by the gross weight of the final (product) formulation.

[0175] However, due to the enhanced chemical stability of the compounds of the present invention towards acidic conditions, it is preferred to use the compounds and compositions of the present invention for the preparation of acid-based formulations and products, such as acidic fragrance oils, fragrance bases, personal hygiene formulations (such as shampoos, shower gels, skin creams and lotions, sunscreens and lotions), cleansers or air fresheners in liquid or gel form or those applied to a solid support (i.e. the formulations and products exhibit an acidic pH, whereby the pH is <7).

[0176] Finally, therefore, the present invention relates to a perfumed product, wherein the perfumed product is preferably a fragrance oil, a fragrance base, a personal hygiene formulation, a cleanser or an air freshener.

[0177] Since such products often contain a large number of chemical ingredients, it is very important that the fragrance compounds or corresponding aromatic compositions also have low chemical reactivity in order to counteract any undesirable interactions or decomposition of the ingredients and / or the fragrance materials. Therefore, the use of the compounds according to the invention is particularly advantageous due to their low reactivity and high stability, especially in acidic media, so that neither the compounds according to the invention nor the ingredients of the fragranced product are adversely affected. In this context, particular emphasis should be placed on the low concentration of fragrance compounds necessary to achieve the desired fragrance effect, which further avoids any undesirable changes in the properties of the fragranced product or its other ingredients.

[0178] In this context, it was surprisingly discovered that molecular modifications directed at rearranging the functionalization within the C1-C4 butyl chain increased chemical stability under acidic conditions and at elevated temperatures, while simultaneously producing a greener and fruitier sandalwood-based scent, resulting in a fresher, more vibrant, and therefore more balanced fragrance. Furthermore, excellent ODT values ​​were achieved. Overall, these compounds are highly suitable for formulating a wide range of acidic products that can be used at elevated temperatures without losing their olfactory quality or intensity.

[0179] Surprisingly, the compounds according to the present invention exhibit a balanced and natural sandalwood-like odor profile, with woody, floral, green, and fruity notes. Furthermore, the compounds according to the present invention, as suitable flavor enhancers or fragrance compounds, exhibit high physicochemical stability, toughness, and a very low odor threshold. Consequently, another advantage of the compounds according to the present invention is that they exhibit high odor intensity at relatively low concentrations.

[0180] Due to their high chemical stability, the compounds of the present invention exhibit a very low tendency to react with other ingredients of the product formulation or other fragrance materials, and therefore do not adversely affect the olfactory and / or chemical properties of the individual components. Such changes in odor characteristics are typically caused, for example, by degradation of the fragrance material due to its insufficient stability, or by the formation of by-products due to chemical interactions between the fragrance material and other ingredients of the formulation / product.

[0181] Example

[0182] The following compounds were prepared starting from camphorenal (Compound 1) according to the methods indicated below and the following general scheme:

[0183]

[0184] Reaction Scheme 1: General synthetic scheme.

[0185] Based on commercially available camphorenal (compound 1), the corresponding 2,2,3-trimethylcyclopent-3-enyl derivative (compound 2, R═H, Me) was synthesized according to the method disclosed in DE 3441902 C1. The synthesis disclosed therein was modified accordingly so that, while initially forming a compound with a C═C double bond between carbon atoms C2 and C3, the compound with a C═C double bond between carbon atoms C3 and C4, as indicated by general formula (I), was also isolated. In a second step, the final product (compound 3, R═H, Me) according to general formula (I) was obtained based on the Simmons-Smith cyclopropanation and the methods described in WO 2017 / 024126 A1 and EP 0801049 B1.

[0186] Structural determination was performed by means of spectroscopy by known techniques.

[0187] As noted above, all compounds and formulae disclosed herein encompass pure stereoisomers, particularly enantiomers, as well as mixtures of stereoisomers, particularly mixtures of enantiomers. Furthermore, all intermediates obtained from the process may occur in different isomeric forms and thus encompass both pure stereoisomers and mixtures of stereoisomers.

[0188] Example 1: Preparation of Compound 3a

[0189] Step 1 : Preparation of 2-ethyl-4-(2,2,3-trimethylcyclopent-3-en-1-yl)but-3-en-1-ol (Compound 2a):

[0190] Compound 2a was prepared according to the method described in DE 3441902 C1.

[0191] Experimental data of 2-ethyl-4-(2,2,3-trimethylcyclopent-3-en-1-yl)but-3-en-1-ol (Compound 2a):

[0192] 1 H NMR (400MHz, CDCl3) δ5.61 (dd, J=15.4, 8.5Hz, 2H), 5.26–5.22 (m, 2H), 5.16 (dtd,J=15.3,8.8,1.0Hz,2H),3.59–3.53(m,2H),3.42–3.34(m,2H),2.45–2 .37(m,2H),2.31–2.22(m,2H),2.18–2.05(m,4H),1.63–1.60(m,6H),1.51–1 .40(m,2H),1.31–1.18(m,2H),0.97(s,6H),0.96–0.85(m,6H),0.77(s,6H).

[0193] 13 C NMR (101MHz, CDCl3) δ148.02,148.02,135.24,134.75,131.78,131.56,121.46,121.46,65.88,65.80,54.34,54.20 ,48.09,48.05,47.83,47.81,35.60,35.30,25.46,25.37,24.08,24.05,20.64,20.50,12.72,12.72,11.81,11.66.

[0194] GC-MS: 208,193,177,161,135,121,107,93,79,55,41,28.

[0195] Step 2 : Preparation of 2-[2-(1,2,2-trimethyl-3-bicyclo[3.1.0]hexyl)cyclopropyl]butan-1-ol (compound 3a, corresponding to general formula (II)):

[0196] Compound 3a was prepared according to the method described in WO 2017 / 024126 A1.

[0197] Experimental data for 2-[2-(1,2,2-trimethyl-3-bicyclo[3.1.0]hexyl)cyclopropyl]butan-1-ol (Compound 3a):

[0198] 1 H NMR (400MHz, CDCl3) δ3.67–3.56(m,4H),1.78–1.62(m,2H),1.65–1.46(m,4H),1.50–1.39(m,2H) ),1.03(s,3H),1.03(s,3H),0.98–0.93(m,2H),0.95(s,6H),0.94(t,J=7.8Hz,3H),0.94(s,3H) ,0.92(t,J=7.8Hz,3H),0.92(s,3H),0.80–0.65(m,2H),0.61(dt,J=10.9,7.9Hz,1H),0.45–0.4 0(m,1H),0.40–0.30(m,6H),0.30–0.22(m,2H),0.20–0.11(m,2H),0.11(dd,J=7.8,4.9Hz,2H).

[0199] 13 C NMR (101MHz, CDCl3) δ66.09,65.46,49.97,49.11,47.18,47.03,41.95,41.72,32.99,31.68,31.52,31.42,24.34,24.27,23 .70,23.25,22.32,22.02,20.72,20.67,19.88,18.90,17.36,17.28,17.11,16.66,13.82,13.78,11.49,11.33,9.87,8.79.

[0200] Scent description: Sandalwood, cedarwood, floral, fruity, creamy, soft, green.

[0201] Additional steps : Isolation of 2-ethyl-4-(1,2,2-trimethyl-3-bicyclo[3.1.0]hexyl)but-3-en-1-ol (by-product, corresponding to general formula (III)):

[0202] The by-product 2-ethyl-4-(1,2,2-trimethyl-3-bicyclo[3.1.0]hexyl)but-3-en-1-ol, a monocyclopropanol, is isolated via conventional methods such as column chromatography.

[0203] Experimental data of 2-ethyl-4-(1,2,2-trimethyl-3-bicyclo[3.1.0]hexyl)but-3-en-1-ol (by-product):

[0204] 1 H NMR (400MHz, CDCl3) δ5.40 (dd, J=15.2, 7.3Hz, 1H), 5.09–5.01 (m, 1H), 3.56–3.50 (m,1H),3.39–3.31(m,1H),2.08(ddt,J=14.6,5.8,3.6Hz,1H),1.86–1.76(m,1H), 1.67(tt,J=12.0,5.7Hz,2H),1.47–1.39(m,1H),1.27–1.16(m,1H),1.04(s,3H), 0.88(t,J=3.7Hz,6H),0.77(s,3H),0.45(q,J=3.5,2.7Hz,1H),0.07–0.04(m,1H).

[0205] 13 C NMR (101MHz, CDCl3) δ134.22,131.42,65.80,47.95,47.86,42.47,31.87,30.95,24.05,22.70,22.62,20.55,17.45,13.97,11.67.

[0206] Odor description: Sandalwood, woody, green, fruity.

[0207] Example 2: Preparation of Compound 3b

[0208] Step 1 : Preparation of 2-methyl-4-(2,2,3-trimethylcyclopent-3-en-1-yl)but-3-en-1-ol (Compound 2b):

[0209] Compound 2b was prepared according to the method described in DE 3441902 C1.

[0210] Experimental data of 2-methyl-4-(2,2,3-trimethylcyclopent-3-en-1-yl)but-3-en-1-ol (Compound 2b):

[0211] 1H NMR (600MHz, CDCl3) δ5.59 (dddd, J=15.6, 8.5, 7.3, 1.0Hz, 2H), 5.28 (dddd, J=15.3, 7.9,1.0Hz,2H),5.25–5.23(m,2H),3.52–3.46(m,2H),3.41–3.36(m,2H),2.41–2. 33(m,4H),2.30–2.22(m,2H),2.14–2.06(m,2H),1.62–1.60(m,6H),1.01(d,J=6.8 Hz, 3H), 1.01 (d, J = 6.8 Hz, 3H), 0.96 (s, 3H), 0.96 (s, 3H), 0.76 (s, 3H), 0.75 (s, 3H).

[0212] 13 C NMR (151MHz, CDCl3) δ148.09,148.03,133.19,133.12,132.97,132.92,121.47,121.44,67.36,67.33,54.16 ,54.05,47.93,47.89,39.94,39.89,35.45,35.42,25.44,25.35,20.56,20.45,16.88,16.70,12.70,12.72.

[0213] GC-MS: 194,179,163,151,135,121,107,93,79,69,55,41,29.

[0214] Step 2 : Preparation of 2-[2-(1,2,2-trimethyl-3-bicyclo[3.1.0]hexyl)cyclopropyl]propan-1-ol (compound 3b, corresponding to general formula (II)):

[0215] Compound 3b was prepared according to the method described in WO 2017 / 024126 A1 or EP 0 801 049 B1.

[0216] Experimental data of 2-[2-(1,2,2-trimethyl-3-bicyclo[3.1.0]hexyl)cyclopropyl]propan-1-ol (Compound 3b):

[0217] 1H NMR (400MHz, CDCl3) δ3.65–3.54(m,2H),3.55–3.45(m,2H),1.65–1.49(m,4 H),1.07(d,J=6.7Hz,3H),1.03(s,3H),1.03(s,3H),0.97(s,3H),0.96–0.9 5(m,3H),0.97–0.94(m,7H),0.94(s,3H),0.91(s,3H),0.51–0.43(m,2H),0 .42–0.31(m,4H),0.38–0.29(m,2H),0.29–0.04(m,4H),0.02–-0.05(m,2H).

[0218] 13 C NMR (101MHz, CDCl3) δ68.72,68.70,49.80,49.71,41.78,41.72,40.97,40.64,32.96,32.06,31.82,31.66,31.61,23 .66,23.31,22.28,22.03,21.28,20.69,20.23,17.34,17.30,17.15,16.70,16.45,16.18,13.86,13.74,10.19,8.97.

[0219] GC-MS: 222,207,181,154,121,107,93,81,67,55,41,29.

[0220] Odor description: Green, floral, fruity, woody, creamy, sandalwood.

[0221] Example 3: Preparation of 2-[2-(2,2,3-trimethylcyclopentyl)cyclopropyl]propan-1-ol (corresponding to general formula (V))

[0222] Step 1 : Synthesis of 2-(2,2,3-trimethylcyclopentyl)acetaldehyde (according to the literature: Helvetica Chimica Acta, 2006, 89(11), 2638-2653):

[0223] The first step in the preparation was hydrogenation of 2-(2,2,3-trimethylcyclopent-3-en-1-yl)acetaldehyde (600.0 g, 253.3 mmol) in an autoclave using a Pd / C (5%) catalyst (30 g) at 80°C and 30 bar. After complete consumption of the hydrogen, the reaction mixture was filtered and evaporated (60°C / 500-10 mbar) to obtain 555 g of the crude product. Subsequent Kugelrohr distillation (85°C, 0.1 mbar) yielded 498 g, or 82% of the intermediate.

[0224] Experimental data of 2-(2,2,3-trimethylcyclopentyl)acetaldehyde:

[0225] 1 H NMR(600MHz,C6D6)δ9.40(dd,J=2.4,1.8Hz,1H),2.02–1.96(m,1H),1.76–1.71(m,2H),1.65–1.61(m,1H),1.61–1.5 6(m,1H),1.32–1.28(m,1H),1.07–1.01(m,1H),0.97–0.92(m,1H),0.74(d,J=6.8Hz,3H),0.67(s,3H),0.29(s,3H).

[0226] 13 C NMR (101MHz, C6D6) δ201.03,45.41,44.74,44.71,41.27,30.36,28.27,25.36,14.57,14.01. GC-MS:139,97,69,41.

[0227] Odor description: Fruity, sweet, aniseed.

[0228] Step 2 :Synthesis of 2-methyl-4-(2,2,3-trimethylcyclopentyl)but-2-enal:

[0229] In the temperature range of 15-20 ℃, to a solution of 2-(2,2,3-trimethylcyclopentyl)acetaldehyde (168.11 g, 1.09 mol) in methanol (300 ml), commercially available 32% NaOH (15.12 mL, 163.47 mmol) was slowly added (exothermic), followed by propionaldehyde (156.5 mL) (exothermic). Thereafter, the addition reaction was maintained at room temperature (about 16 h). Subsequently, the reaction was terminated with water (400 ml), the pH was neutralized with sulfuric acid, and methanol was removed by distillation under reduced pressure. The crude compound obtained was extracted with MTBE (300 mL×3), and the organic layers were combined and washed with a saturated solution of ammonium chloride (300 mL) and sodium chloride (300 mL). The combined organic layers were further washed with water until the aqueous phase had a neutral pH value, then dried under Na2SO4, filtered, and MTBE was removed using a rotary evaporator to obtain 261.73 g of crude product. The above crude product (R T =140-210℃, H T =90-122°C, vacuum = 5 mbar) to give 83.8 g of the title compound.

[0230] Experimental data of 2-methyl-4-(2,2,3-trimethylcyclopentyl)but-2-enal:

[0231] 1 H NMR(400MHz, CDCl3)δ9.39(s,1H),6.53(tq,J=7.5,1.4Hz,1H),2.49–2.40(m,1H),2.13(ddd,J=14.4,10.5,7.6Hz,1H),1.88 –1.72(m,2H),1.76(d,J=1.3Hz,3H),1.62–1.48(m,2H),1.29–1.17(m,2H),0.93(s,3H),0.86(d,J=6.8Hz,3H),0.59(s,3H).

[0232] 13 C NMR (101MHz, CDCl3) δ195.46,155.24,139.17,50.34,44.91,42.59,30.31,29.94,28.20,25.67,14.49,13.91,9.29.

[0233] GC-MS: 194,179,161,137,123,109,95,84,69,55,41,29.

[0234] Step 3: Synthesis of 2-methyl-4-(2,2,3-trimethylcyclopentyl)but-3-en-1-ol (synthesis according to document: DE3441902):

[0235] According to the procedure disclosed in DE 3441902, 2-methyl-4-(2,2,3-trimethylcyclopentyl)but-2-enal (42.2 g, 161.6 mmol) was heated to 60° C. in methanol (80 ml), and a pre-dissolved solution of NaBH 4 (2.0 g, 51.7 mmol) in 15 ml of 1%-NaOH was slowly added at 60° C. for 1 hour, followed by an additional 1 hour at room temperature. Subsequently, the reaction mixture was evaporated (60° C. / 350-150 mbar) and the methanol removed, followed by extraction with MTBE (100 mL×3). The organic layer was washed with saturated NaCl solution (100 mL), dried over Na2SO4 and filtered, and MTBE was removed using a rotary evaporator (40°C / 500-30 mbar), followed by Kugelrohr distillation (120°C, 0.8 mbar) to give 30 g of product, a mixture of 2-methyl-4-(2,2,3-trimethylcyclopentyl)but-3-en-1-ol and 2-methyl-4-(2,2,3-trimethylcyclopentyl)but-2-en-1-ol (1:5). Spaltroh distillation (R T =70-85℃, H T =75-95, vacuum = 1 mbar), yielding 8% of the title compound.

[0236] Experimental data of 2-methyl-4-(2,2,3-trimethylcyclopentyl)but-3-en-1-ol:

[0237] CG-MS:196,181,163,111,95,81,69,55,41,29.

[0238] Step 4 : Synthesis of 2-[2-(2,2,3-trimethylcyclopentyl)cyclopropyl]propan-1-ol (synthesis according to document: WO2017 / 024126):

[0239] Synthesis based on literature starting from 2-methyl-4-(2,2,3-trimethylcyclopentyl)but-3-en-1-ol (2.85 g, 14.5 mmol) gave 1.62 g of the title compound after purification by Kugelrohr distillation (122-130° C., 22 mbar).

[0240] Experimental data for 2-[2-(2,2,3-trimethylcyclopentyl)cyclopropyl]propan-1-ol:

[0241] 1H NMR(600MHz,C6D6)δ3.45(dd,J=10.3,5.3Hz,1H),3.30(t,J=10.3Hz,1H),1.74–1.63(m,2H), 1.48–1.31(m,2H),1.21–1.13(m,1H),1.03(d,J=6.8Hz,3H),0.97(s,3H),0.85(d,J=6.8Hz,3 H),0.80–0.73(m,1H),0.69(s,3H),0.61(dt,J=10.9,8.8Hz,1H),0.31(ddt,J=9.4,8.1,4.8H z, 1H), 0.25 (tt, J = 9.4, 4.7Hz, 1H), 0.16 (dt, J = 8.6, 4.9Hz, 1H), 0.04 (dt, J = 8.1, 4.9Hz, 1H).

[0242] 13 C NMR (151MHz, C6D6) δ68.26,56.21,45.76,43.14,41.56,30.05,28.24,26.45,21.45,17.44,17.21,15.27,14.10,9.16.

[0243] GC-MS: 210,195,177,149,137,123,109,95,82,69,55,41,29.

[0244] Scent Description: Cedarwood, Sandalwood, Creamy.

[0245] Example 4 Comparison of Chemical Stability

[0246] Example 4 shows the reaction of compounds of the invention of general formula (I) and more specifically general formula (II) with commercially available [1-methyl-2-[(1,2,2-trimethyl-3-bicyclo[3.1.0]hexyl)methyl]cyclopropyl]methanol (also known as Givaudan) in acidic conditions.

[0247] To analyze the stability of the compounds of the present invention, 0.3% of compound 3a, compound 3b or Different samples of FLAVOR® (Givaudan) were analyzed, i.e., stability tests were performed using a representative acidic detergent (pH = 2) in which the corresponding fragrance compound was spiked at 0.3% relative to the acidic detergent.

[0248] Each sample containing one of the fragrance compounds indicated above was subjected to stability analysis via solid phase microextraction (SPME) and gas chromatography-mass spectrometry (GC-MS) using a combination of polydimethylsiloxane and divinylbenzene as the SPME fiber coating (PDMS / DVB fiber) and a polydimethylsiloxane-based DB-1 column for gas chromatography analysis (100% polydimethylsiloxane). Each sample was subjected to stability testing after 14 days of acid treatment at different storage temperatures (6°C, 22°C, 40°C and 50°C) compared to a freshly prepared sample as a reference (see Figure 1 ).

[0249] The results of the above comparison are Figure 1 As shown in the figure, when treated under acidic conditions for 14 days, compounds 3a and 3b of the present invention showed better acid stability over the entire temperature range. The best stability was observed for samples treated under acidic conditions at a temperature of 22°C for 14 days, and especially for compound 3a treated at a temperature of 22°C, while (Givaudan) appears to decompose rapidly even at moderate temperatures after treatment with an acidic medium and decomposes completely when treated at 50°C under acidic conditions for 14 days.

[0250] For example, pH balanced shower gel products are also adjusted to a pH of approximately 5.5. When showering or washing, the water temperature is typically set to a temperature of approximately 40°C, and the fragrance components should not decompose within the shower gel formulation or while using the shower gel or other fragranced product. Furthermore, it has been found that human sweat generally has a moderately acidic to neutral pH level, and typically has a pH value of approximately 4.5. Moreover, the pH exhibited by the natural skin surface is on average below 5. In addition, our skin is often exposed to higher temperatures, such as those caused by the sun (especially in the summer). These are just some of the many situations in which fragrance compounds are exposed to acidic conditions and / or elevated temperatures. However, based on the above experiments, the following conclusions can be drawn, which are consistent with (Givaudan), the compounds of the present invention of general formula (I) are expected to have considerably higher stability in such products or on the skin, without generating unpleasant odors or changing the odor characteristics due to decomposition of the fragrance material or its reaction with other ingredients of the formulation and formation of by-products, thereby providing a stable fragrance material (especially under acidic conditions).

[0251] The increased stability can be explained based on the position of the cyclopropanation relative to the group R (which is H or methyl in compounds 3a and 3b, respectively, see compounds of formula (II)) within the side chain of the molecule: although the cyclopropane ring is located (Givaudan) between the carbon atoms marked C2 and C3, but with reference to the general formula (I) of the compounds of the present invention, the cyclopropane ring within the butyl chain C1-C4 encompasses the carbon atoms marked C3 and C4. However, in In Givaudan, the C2 atom is already bound to either methyl group, which, combined with the relatively high ring strain of the cyclopropane ring, can cause the molecule to become unstable under acidic conditions and elevated temperatures, leading to decomposition of the fragrance material. The instability of the molecule upon exposure to elevated temperatures and acidic conditions results in a loss of olfactory properties and may produce unpleasant odors due to decomposition products and / or interactions with other ingredients in the formulation.

Claims

1. Compounds of formula (II): in R represents H or a methyl, ethyl, propyl, n-butyl or isobutyl group; or a mixture of the above compounds.

2. A fragrance composition comprising at least one compound according to claim 1 and at least one additional fragrance material.

3. A perfumed product comprising the compound according to claim 1 or the perfume composition according to claim 2.

4. A perfumed product comprising an effective amount of the compound according to claim 1 or the perfume composition according to claim 2, and a carrier or base.

5. The perfumed product according to claim 3 or the perfumed product according to claim 4, wherein the perfumed product is a fragrance oil, a fragrance base, a personal hygiene formulation, a cleanser or an air freshener.

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