The present invention relates to fragrance precursors. These fragrance precursors are able to release (E/Z)-9-hydroxy-5,9-dimethyldec-4-enal. Furthermore, the invention relates to the use of such fragrance precursors in perfume preparations. In particular, the invention relates to fragrance precursors or perfume preparations containing said precursors that release fragrance with muguet (lily of the valley) odour characteristics. Still more particularly, the invention relates to said perfume preparations that contain no, or substantially no, Lyral™. The invention further relates to methods of making said perfume precursors and perfume preparations, as well as the use of said perfume precursors and perfume preparations in fine fragrances and consumer products, such as personal care and household care products. The invention also relates to said fine fragrances and consumer products containing said perfume precursors and perfume preparations.

Compounds having muguet odour characteristics are very sought after as perfume ingredients. These compounds are important ingredients in floral bases and can act as harmonizers across many types of fragrance creations. Compounds of this type are used widely in personal care and consumer care products, as well as in fine perfumery, to generate pleasant odours or to mask unpleasant odours.

An excellent perfume ingredient widely valued for its muguet odour note is 4(4- hydroxy-4-methylpentyl) 3-cyclohexene carboxaldehyde, also known as cyclohexal (Lyral™). This compound has found wide use in fine perfumery as well as in personal and household care products. However according to findings of the European Scientific Committee for Consumer Safety (SCCS) it has allergenic concerns and at the present time may be subject to regulatory action in the EU. Recently, applicant has found a novel compound (E/Z)-9-hydroxy-5,9-dimethyldec- 4-enal that can be employed as a perfume ingredient in perfume compositions and fine fragrances and consumer products. The novel compound possesses desirable classic floral, green muguet odour characteristics and may be perceived and recognised by perfumers as being very reminiscent of the odour of Cyclohexal (Lyral™) and so can serve as a simple replacement for Lyral™. Details of this invention are disclosed in international patent application PCT/EP2014/062002, which is hereby incorporated by reference

Perfumed products such as cleaning or laundry products comprising Lyral™ are well-known in the art.

However, it is known that fragrances can be altered through degradation caused by interaction with air or when incorporated in certain consumer product bases, where alkalinity, acidity, the presence of oxidizing agents, such as hypochlorite salts, or other base components may lead to chemical degradation of the fragrance. In addition, volatile fragrances tend to be dissipated with time. Furthermore, when used in cleaning or laundry products, the deposition of the fragrance on a treated substrate is diminished by the washing and/or rinsing procedure.

Nevertheless, it is desired by consumers to have products that can be stored over time and still giving a constant perfume impression. In particular, the impact of volatile components is to be retained. Furthermore, it is desired that such products create a long-lasting pleasing fragrance slowly emitting from the treated substrate over time.

Therefore, it is an objective of the present invention to provide a system which is capable of releasing the above mentioned Lyral™ type fragrance constantly over time and providing a long-lasting release of said fragrance. It is another objective of the present invention to increase the substantivity of (E/Z)-9-hydroxy-5,9-dimethyldec-4-enal, in particular in consumer product applications, especially in the so-called rinse off applications, like fabric softener or conditioner, as well as in hair shampoo or fabric detergents.

Applicant has found that derivatives of (E/Z)-9-hydroxy-5,9-dimethyldec-4-enal can serve as fragrance precursors of (E/Z)-9-hydroxy-5,9-dimethyldec-4-enal. These fragrance precursors provide a delayed release of (E/Z)-9-hydroxy-5,9- dimethyldec-4-enal over a longer period of time than by the use of the fragrance itself.

Accordingly, the invention provides in a first aspect a compound represented by formula 1

formula 1 wherein

the wavy bond is indicating an unspecified configuration of the adjacent double bond,

X and Y together represent a double bond to a carbon atom which is bearing Ri and R ₂ , with Ri = H, methyl, acetyl or Ci-C ₃ alkoxycarbonyl (e.g. ethoxycarbonyl); and

R ₂ = phenyl optionally substituted with up to 3 (i.e. 0, 1, 2 or 3) groups selected from Ci-C ₄ alkyl (e.g. methyl, ethyl, iso-propyl, tert-butyl), vinyl, hydroxy, Ci-C ₃ alkoxy (e.g. ethoxy), and -0-CH ₂ -0-, e.g. R ₂ is benzo[d][l,3]dioxol-5-yl, 4- methylphenyl, 4-methoxyphenyl, 4-vinylphenyl or 3-ethoxy-4-hydroxyphenyl or R ₂ = naphthyl, (naphthyl)methyl, l,l,2,4,4,8-hexamethyl-l,2,3,4- tetrahydronaphthalen-7-yl, or 1,1,2,4,4,-pentamethyl- 1,2,3,4- tetrahydronaphthalen-7-yl

or

R ₂ = COR ₃ , wherein R ₃ is H, Ci-C ₁₀ alkoxy (e.g. ethoxy, l-(3,3- dimethylcyclohexyl)ethoxy), CrC ₄ alkyl (e.g. methyl, ethyl, propyl, iso-propyl, tert- butyl), e.g. R ₂ is formyl, acetyl, ethoxycarbonyl, l-(3,3- dimethylcyclohexyl)ethoxycarbonyl;

or wherein

X is OR ₄ , with R ₄ being H, Me or a branched or linear, saturated or unsaturated C ₂ -

C ₅ alkyl or alkenyl residue (e.g. ethyl, propyl, iso-propyl, tert-butyl), and

Y is OR ₅ , with R ₅ being Me or a branched or linear, saturated or unsaturated C ₂ -C ₅ alkyl or alkenyl residue (e.g. ethyl, propyl, iso-propyl, tert-butyl), or

R ₄ and R5 forming, together with the acetal carbon and oxygen atoms, a 5- or 6- membered ring, which optionally may be substituted with a methyl or hydroxymethyl substituent, yielding a glycerol acetal.

The wavy bond is indicating an unspecified configuration of the double bond. More specifically, this wavy bond signifies a molecule which has an E or a Z- configuration, or is a mixture of E- and Z-isomers.

The compounds represented by formula 1 as described above are suitable fragrance precursors.

The said fragrance precursors are able to release (E/Z)-9-hydroxy-5,9-dimethyldec- 4-enal, a compound with substantially similar odour characteristics and performance characteristics as Lyral ™. The precursors provide an improved fragrance intensity and a long-lasting release (also known as substantivity) of (E/Z)-9-hydroxy-5,9-dimethyldec-4-enal. According to the present invention, a fragrance precursor is a substance that is not itself a final fragrance, but which, in particular circumstances will break down to give at least one desired fragrant substance. The fragrance precursor will release the desired fragrance for example by hydrolysis with air moisture or water. The release can also be caused by exposure to light or oxygen, pH change and enzymatic activity.

The fragrance precursor itself can be odourless. Alternatively, the precursor may be an odorant on its own.

Furthermore, the precursors are substantially odourless or have pleasant odour characteristics that may improve odour properties of the overall fragrance, respectively. It is important that the odour properties of the overall fragrance are not affected, or are not adversely affected, by the presence of the reaction product.

In one of the aspects of the invention, it is preferred that the fragrance precursor is a compound represented by formula 2

formula 2 wherein

the wavy bonds are indicating an unspecified configuration of the adjacent double bond, respectively,

Ri = H, methyl, acetyl or Ci-C ₃ alkoxycarbonyl (e.g. ethoxycarbonyl); and

R ₂ = phenyl optionally substituted with up to 3 (i.e. 0, 1, 2 or 3) groups selected from CrC ₄ alkyl (e.g. methyl, ethyl, iso-propyl, tert-butyl), vinyl, hydroxy, Ci-C ₃ alkoxy (e.g. ethoxy), and -0-CH ₂ -0-, e.g. R ₂ is benzo[d][l,3]dioxol-5-yl, 4- methylphenyl, 4-methoxyphenyl, 4-vinylphenyl or 3-ethoxy-4-hydroxyphenyl or

R ₂ = naphthyl, (naphthyl)methyl, l,l,2,4,4,8-hexamethyl-l,2,3,4- tetrahydronaphthalen-7-yl, or 1,1,2,4,4,-pentamethyl- 1,2,3,4- tetrahydronaphthalen-7-yl

or

R ₂ = COR ₃ , wherein R ₃ is H, Ci-C ₁₀ alkoxy (e.g. ethoxy, l-(3,3- dimethylcyclohexyl)ethoxy), CrC ₄ alkyl (e.g. methyl, ethyl, propyl, iso-propyl, tert- butyl), e.g. R ₂ is formyl, acetyl, ethoxycarbonyl, l-(3,3- dimethylcyclohexyl)ethoxycarbonyl.

The described fragrance precursor represented by formula 2 may be synthesized in one step from (E/Z)-9-hydroxy-5,9-dimethyldec-4-enal.

For example, the fragrance precursor represented by formula 2 can be prepared via a Wittig reaction with (E/Z)-9-hydroxy-5,9-dimethyldec-4-enal and a phosphorous ylide derived in situ from a benzyltriphenyl-phosphonium-halogen salt.

In another embodiment of the invention, the fragrance precursor represented by formula 2 can be derived from a Knoevenagel- or /4/c/o/-condensation reaction with (E/Z)-9-hydroxy-5,9-dimethyldec-4-enal and an alkyl acetoacetate, a dialkyl malonate or acetone under reaction conditions known in the art.

It is preferred to use a fragrance precursor as a prepared compound represented by formula 2 in a perfume mixture. However, in another aspect of the invention, it is possible to form said fragrance precursor directly in the perfume mixture by adding the starting compounds into the perfume mixture. For example, after addition of (E/Z)-9-hydroxy-5,9-dimethyldec-4-enal and ethyl acetoacetate into a perfume mixture, the corresponding fragrance precursor ethyl 2-acetyl-ll-hydroxy- 7,ll-dimethyldodeca-2,6-dienoate, that is a compound represented by formula 2, is formed.

In another of the aspects of the invention, it is preferred that the fragrance precursor is a compound represented by formula 3

formula 3 with R ₄ being H, Me or a branched or linear, saturated or unsaturated C2-C5 alkyl or alkenyl residue (e.g. ethyl, propyl, iso-propyl, tert-butyl),

R ₅ being Me or a branched or linear, saturated or unsaturated C2-C5 alkyl or alkenyl residue (e.g. ethyl, propyl, iso-propyl, tert-butyl), or

R ₄ and R5 forming, together with the acetal carbon and oxygen atoms, a 5- or 6- membered ring, which optionally may be substituted with a methyl or hydroxymethyl substituent, yielding a glycerol acetal; and

the wavy bond indicating an unspecified configuration of the adjacent double bond.

For example, compounds of formula 3 may be synthesized by treating (E/Z)-9- hydroxy-5,9-dimethyldec-4-enal with suitable alcohols HOR ₄ and/or HOR5 under acidic conditions at reflux.

Such acetals or hemi-acetals represented by formula 3 can be prepared and added to a perfume mixture. In a further aspect of the invention, they may be formed directly in the perfume mixture by addition of the starting compounds to the perfume mixture.

In another of its aspects, the invention provides the use of the described fragrance precursors according to formula 1, 2 or 3 as a perfume ingredient. In particular, the precursor as perfume ingredient can release an ingredient with muguet odour characteristics.

As such, the present invention provides a precursor that can release a single fragrance compound for a Lyral™ replacement. Such a replacement by a single fragrance might be cost-effective and convenient for a perfumer.

The invention provides in another of its aspects the use of the described fragrance precursor in a perfume composition that is able to release (E/Z)-9-hydroxy-5,9- dimethyldec-4-enal as a replacement for Lyral™.

As such, the fragrance precursor releasing (E/Z)-9-hydroxy-5,9-dimethyldec-4-enal provides perfumers with an eminently suitable surrogate for the valuable yet problematic Lyral™.

In a further aspect of the invention, there is provided a precursor suitable for replacement of Lyral™ precursors.

In another aspect of the invention there is provided a method of imparting a muguet odour characteristic to a perfume composition, said method comprising the step of incorporating a fragrance precursor that is able to release (E/Z)-9-hydroxy- 5,9-dimethyldec-4-enal into said perfume composition.

In yet another aspect of the invention there is provided a perfume composition comprising a fragrance precursor represented by formula 1 that is able to release (E/Z)-9-hydroxy-5,9-dimethyldec-4-enal into said perfume composition.

In yet another aspect of the invention there is provided a perfume composition possessing muguet odour characteristics comprising a fragrance precursor represented by formula 1 that is able to release (E/Z)-9-hydroxy-5,9-dimethyldec- 4-enal. In yet another aspect of the present invention there is provided a perfume composition comprising a fragrance precursor that is substantially free of Lyral™.

A perfume composition according to the present invention can be made up entirely by the fragrance precursor represented by formula 1. However, a perfume composition may also contain, in addition to the said fragrance precursor, one or more additional perfume ingredients.

The fragrance precursor according to formula 1 may be present in a perfume composition in any amount depending on the particular olfactive effect that a perfumer wishes to achieve. In a particular embodiment of the present invention, a perfume composition of the present invention may contain the said fragrance precursor in an amount of 0.1 to 100 % by weight of said composition.

It is particularly preferred, that the perfume composition further comprises ( /Z)-9- hydroxy-5,9-dimethyldec-4-enal. The mixture of the fragrance and a precursor releasing said fragrance ensures a constant and long-lasting fragrance impression over time.

The perfume composition may further comprise additional perfume ingredients. If one or more additional perfume ingredients are employed, they may be selected from any known perfume ingredients or from their precursor systems, respectively.

In particular, said perfume ingredients that may be employed in a perfume composition according to the invention include 3-(4-isobutyl-2- methylphenyl)propanal; 2-cyclohexylidene-2-phenylacetonitrile, e.g. PEONILE ™; 4-(octahydro-4,7-methano-5H-inden-5-ylidene)butanal, e.g. DUPICAL™; 4-methyl- 2-(2-methylpropyl)tetrahydro-2H-pyran-4-ol, e.g. FLOROSA™; and methyl 2-(2- hexyl-3-oxocyclopentyl)acetate, e. g. HEDIONE™.

Furthermore, perfume ingredients that may be employed in a perfume composition according to the invention include: Natural ingredients, such as those selected from Iris, Mimosa, Ylang, Bergamot, jasmine and rose;

Synthetic muguet fragrance ingredients such as Cyclamen aldehyde (103-95-7), Hydroxycitronellal (107-75-5), Hydroxy Citronellal diethyl acetal (7779-94-4), Lilial (80-54-6), Cyclohexal (31906-04-4), Silvial (6658-48-6), Bourgeonal (18127-01-0), Florhydral (125109-85-5), and Cyclemax (7775-00-0);

Harmonic floral ingredients of the rose type such as ethyl phenyl alcohol (60-12-8), Dimethyl phenyl ethyl carbinol (103-05-9), Citronellol (106-22-9), Rhodinol (106- 22-9), Acet. DMBC (151-05-3), Geraniol (106-24-1), Nerol (106-25-2), Nerolidol (7212-44-4), Mefrosol (55066-48-3), Peomosa (19819-98-8), citronellyl iso butyrate (97-89-2), and Majantol (103694-68-4);

Harmonic foral ingredients of the freesia type such as Linalool (78-70-6), Rossitol (215231-33-7), and Coranol (83926-73-2);

Harmonic floral ingredients of the lilac type such as Ale. Cinnamic alcohol (104-54- 1), propyl phenyl alcohol (122-97-4) and Terpineol (8000-41-7);

Harmonic floral ingredients of the jasmine type such as benzyl acetate (140-11-4), Hedione (24851-98-7), Hexyl Cinnamic aldehyde (101-86-0), and Amyl Cinnamic aldehyde (122-40-7);

Harmonic floral ingredients of the muguet type such as Super Muguet (26330-65- 4), Hydroxycitronellal dimethyl acetate (141-92-4), Magnol (92046-49-6), Mugetanol (63767-86-2), Mugesia (56836-93-2), Indole (120-72-9), and Indolene (67860-00-8);

Green harmonic ingredients such as cis 3 Hexenol (928-96-1), phenyl acetic aldehyde (122-78-1), Maceal (67845-30-1), cis 3 hexenyl acetate (3681-71-8), Acetal CD (29895-73-6), Precarone (74499-58-4), Mefranal (55066-49-4), Elintaal (40910-49-4), Glycolierral (68901-32-6), and Coranol (83926-73-2);

Fresh harmonic ingredients such as Cll undecelenic aldehyde (112-45-8), Cll undecylic aldehyde (112-44-7), C 10 aldehyde (112-31-2), C 12 MNA aldehyde (110-41-8), Tropional (1205-17-0), Citral (5392-40-5), Oxyde de Limette (73018- 51-6), Florhydral (125109-85-5), Floralozone (67634-15-5), Dihydro Farnesal (51513-58-7), Dihydrofarnesol (51411-24-6), Adoxal (141-13-9), Citronellyl Oxyacetaldehyde (7492-67-3), Floral super (71077-31-1) and Dodecenal (4826-62-

4) ;

Harmonic woody ingredients such as Irisone (8013-90-9) and methyl lonone (1335-46-2);

Harmonic powdery ingredients such as Fixolide (21145-77-7), Thibetolide (106-02-

5) , Heliotropine (120-57-0) and Vanilline (121-33-5); and

Diverse harmonic floral ingredients such as Phixia (107-75-5), Farnesal (19317-11- 4), Farnesyle acetate (29548-30-9), Rhodinyl acetate (141-11-7), Cyclomethylene Citronellol (15760-18-6), Mayol (5502-75-0), Myraldyl acetate (72403-67-9), and Melonia (3613-30-7), wherein the CAS numbers of the molecules are provided in parentheses.

In addition to the aforementioned perfume ingredients that may be employed as being particularly complimentary to the odour characteristics of the compound of formula (I), other fragrance ingredients commonly used in perfumery may be employed, for example any of those ingredients described in "Perfume and Flavour Chemicals", S. Arctander, Allured Publishing Corporation, 1994, IL, USA, which is incorporated herein by reference, including essential oils, plant extracts, absolutes, resinoids, odourants obtained from natural products and the like. However, it is preferred that the perfume compositions contain no, or substantially no, Cyclohexal.

The perfume ingredients contained in said perfume compositions are described above, but of course, the perfume mixture may not be limited to the stated ingredients. In particular, perfume compositions may comprise adjuvants that are commonly employed in perfume compositions. The term "adjuvants" refers to ingredients that might be employed in a perfume composition for reasons not specifically related to the olfactive performance of said composition. For example, an adjuvant may be an ingredient that acts as an aid to processing a perfume ingredient or ingredients, or a composition containing said ingredient(s), or it may improve handling or storage of a perfume ingredient or composition containing same. It might also be an ingredient that provides additional benefits such as imparting colour or texture. It might also be an ingredient that imparts light resistance or chemical stability to one or more ingredients contained in a perfume ingredient or composition containing same. A detailed description of the nature and type of adjuvants commonly used in perfume compositions containing same cannot be exhaustive, but it has to be mentioned that said ingredients are well known to a person skilled in the art. Examples of adjuvants include solvents and co-solvents; surfactants and emulsifiers; viscosity and rheology modifiers; thickening and gelling agents; preservative materials; pigments, dyestuffs and colouring matters; extenders, fillers and reinforcing agents; stabilisers against the detrimental effects of heat and light, bulking agents, acidulants, buffering agents and antioxidants.

In a particular embodiment of the present invention a composition comprising a fragrance precursor, that is an aminal and/or enamine of (E/Z)-9-hydroxy-5,9- dimethyldec-4-enal, or perfume composition containing same, as herein defined, contains an anti-oxidant adjuvant. Said anti-oxidant may be selected from Tinogard® TT (BASF), Tinogard® Q (BASF), Tocopherol (including its isomers, CAS 59-02-9; 364-49-8; 18920-62-2; 121854-78-2), 2,6-bis(l,l-dimethylethyl)-4- methylphenol (BHT, CAS 128-37-0) and related phenols, hydroquinones (CAS 121- 31-9). More specifically, Tinogard Q in triethyl citrate (TEC) can be preferentially used as an antioxidant of released (E/Z)-9-hydroxy-5,9-dimethyldec-4-enal. The antioxidants may be applied in levels of 0.01 to 3%, preferably 0.1 to 1.5 % by weight of the fragrance precursor. Applicant found that unless precautions are taken to prevent excessive oxidation of (E/Z)-9-hydroxy-5,9-dimethyldec-4-enal, undesirable levels of oxidation products can be produced. Accordingly, an antioxidant may be employed in combination with the fragrance precursor described above that is able to release (E/Z)-9-hydroxy-5,9-dimethyldec-4-enal.

Furthermore, any one or more of the perfume ingredients or adjuvants employed in the present invention might be formulated in a delivery vehicle if desired to provide a desired effect. Delivery vehicles may include encapsulates. Alternatively, a delivery vehicle may be in the form of a solid support, e.g. a polymeric support material onto which one or more perfume ingredients or adjuvants may be chemically or physically bound. Still further, one or more perfume ingredients or adjuvants may be dissolved or dispersed in a matrix material, which serves to control the rate at which said ingredient or ingredients emanates therefrom. In yet an alternative embodiment, one or more ingredients or adjuvants may be supported on a porous substrate, such as a cyclodextrin or a zeolite or other inorganic material. In a still further embodiment, one or more perfume ingredients may be provided in the form of a pro-perfume or precursor, which will react in a suitable environment to release the perfume ingredient in a controlled manner.

Having regard to the foregoing, it will be appreciated that a perfume composition may be at least partly in solid form, in gel form, in foam form and/or liquid form. If it is present in solid form, it then it may take the form of granules, powders or tablets. The fragrance precursor or perfume compositions described herein, may be employed to add a characteristic odour, in particular a muguet odour, to all manner of personal care and household care compositions that will be released with time.

According to another aspect of the present invention there is provided a method of imparting muguet odour characteristics to a composition comprising the step of adding to said composition a fragrance precursor that is able to release ( /Z)-9- hydroxy-5,9-dimethyldec-4-enal or a perfume composition containing said fragrance precursor.

A fragrance precursor as a perfume ingredient, or when used in perfume compositions can generate particularly substantive and long-lasting muguet odour characteristics. The compound released by the precursor, (E/Z)-9-hydroxy-5,9- dimethyldec-4-enal, is a particularly impactful perfume ingredient.

Consumer products such as personal and household care compositions include, but are not limited to a textile treatment product, an ironing aid, a cleaning cloth, a laundry detergent, a cleaning product, in particular, for hard and/or soft surfaces, a household cleaner, a care product, a wash care product, a laundry care product, a room fragrancer, and air freshener, a conditioner, a colorant, a fabric conditioner, a conditioning substrate, a pharmaceutical, a crop protection product, a polish, a food, a cosmetic product, a fertilizer, a building material, an adhesive, a bleach, a decalcifier, an autocare product, floorcare product, cookercare product, leathercare product or furniture care product, a scourer, a disinfectant, a fragrancer, a mold remover and/or a precursor of the aforementioned products.

The skilled person is fully aware of the applicability of perfume ingredients, and compositions to personal and house hold care compositions and a very detailed description of such compositions is not warranted here. However, specific compositions that can be mentioned include cleaning compositions; autocare compositions; Cosmetic compositions; textile treatment compositions; and air freshener and air care compositions.

Cleaning products include:-

Toilet cleaners or lavatory cleaners, in other words, products for cleaning lavatory bowls and urinals, these products being supplied preferably in the form of powders, blocks, tablets or liquids, preferably gels. Besides other typical ingredients such as surfactants, they generally include organic acids e.g., citric acid and/or lactic acid) or sodium hydrogen sulfate, amidosulfuric acid or phosphoric acid for removing limescale or urine scale;

Pipe-cleaning products or drain cleaners. These are typically strongly alkaline products which serve in general to remove pipe blockages comprising organic materials-such as hair, fat, food residues, soap deposits, and the like. Additions of Al powder or Zn powder may serve for the formation of H2 gas with an effervescence effect. Possible ingredients are commonly alkalis, alkaline salts, oxidizing agents, and neutral salts. Supply forms in powder form preferably also include sodium nitrate and sodium chloride. Pipe-cleaning products in liquid form may preferably also include hypochlorite. There are also enzyme-based drain cleaners as well. Acidic products are likewise possible;

Universal or all-purpose or general-purpose cleaners. These are cleaners which can be used universally for all hard surfaces in the household and in commerce that can be wiped down wet or damp. Generally speaking, they are neutral or slightly alkaline or slightly acidic products, especially liquid products. All-purpose or general-purpose cleaners generally contain surfactants, builders, solvents and hydrotropes, dyes, preservatives, and the like; All-purpose cleaners with special disinfectant properties. They additionally include active antimicrobial ingredients (e.g., aldehydes, alcohols, quaternary ammonium compounds, amphoteric surfactants, triclosan);

Sanitary cleaners. These are products for cleaning in bath and toilet. The alkaline sanitary cleaners are used preferably for removing fatty soiling, whereas the acidic sanitary cleaners are employed in particular, for removing limescale. Sanitary cleaners advantageously also have a considerable disinfectant action, particularly the strongly alkaline sanitary cleaners that contain chlorine;

Oven cleaners or grill cleaners which may be supplied in the form of gels or foam sprays. They generally serve for removing burnt-on or carbonized food residues. Oven cleaners are preferably given a strongly alkaline formulation using, for example, sodium hydroxide, sodium metasilicate, 2-aminoethanol. In addition they generally contain anionic and/or nonionic surfactants, water-soluble solvents, and, in some cases, thickeners such as polycarboxylates and carboxymethylcellulose;

Metal polishes. These are cleaners for particular types of metal such as stainless steel or silver. Stainless steel cleaners preferably contain, besides acids (preferably up to 3% by weight, e.g., citric acid, lactic acid), surfactants (in particular, up to 5% by weight, preferably nonionic and/or anionic surfactants), and water, solvents as well (preferably up to 15% by weight) to remove fatty soiling, and also further compounds such as thickeners and preservatives. Very fine polishing structures are included, furthermore, in products for preferably bright stainless steel surfaces. Silver polishes, in turn, may be provided in an acidic formulation. In particular, for removing black deposits of silver sulfide they contain, preferably, complexing agents (e.g., thiourea, sodium thiosulfate). Typical supply forms are polishing cloths, dipping baths, pastes, and liquids. Dark discolorations (oxide layers) are removed using copper cleaners and nonferrous-metal cleaners (e.g., for brass and bronze). They generally have a weakly alkaline formulation (preferably with ammonia) and in general contain polishing agents and also, preferably, ammonium soaps and/or complexing agents;

Glass cleaners and window cleaners. These products serve preferably to remove dirt, especially greasy dirt, from glass surfaces. Preferably they contain compounds such as anionic and/or nonionic surfactants (in particular, up to 5% by weight), ammonia and/or ethanolamine (in particular, up to 1% by weight), ethanol and/or 2-propanol, glycol ethers (in particular, 10-30% by weight), water, preservatives, dyes, anti-misting agents and the like; and

Special-purpose cleaning products, examples being those for glass-ceramic hobs, and also carpet cleaners and stain removers.

Autocare products include:-

Paint preservers, paint polishes, paint cleaners, wash preservers, shampoos for auto washing, auto-wash and wax products, polishes for trim metals, protective films for trim metals, plastics cleaners, tar removers, screen cleaners, engine cleaners, and the like.

Cosmetic products include:-

(a) cosmetic skincare products, especially bath products, skin washing and cleansing products, skincare products, eye makeup, lip care products, nail care products, intimate care products, foot care products;

(b) cosmetic products with specific effects, especially sunscreens, tanning products, de-pigmenting products, deodorants, antiperspirants, hair removers, shaving products, perfumes;

(c) cosmetic dental-care products, especially dental and oral care products, tooth care products, cleaners for dental prostheses, adhesives for dental prostheses; and (d) cosmetic hair care products, especially hair shampoos, hair care products, hair setting products, hair-shaping products, and hair coloring products.

Textile treatment products include:-

Detergents or fabric conditioners, for example, in either liquid or solid form. Air fresheners and room fragrancers include:-

Products that contain preferably volatile and usually pleasant-smelling compounds which advantageously can even in very small amounts mask unpleasant odours. Air fresheners for living areas contain, in particular, natural and synthetic essential oils such as pine needle oils, citrus oil, eucalyptus oil, lavender oil, and the like., in amounts for example of up to 50% by weight. As aerosols they tend to contain smaller amounts of such essential oils, by way of example less than 5% or less than 2% by weight, but additionally include compounds such as acetaldehyde (in particular, <0.5% by weight), isopropyl alcohol (in particular, <5% by weight), mineral oil (in particular, <5% by weight), and propellants. Other presentation forms include sticks and blocks. They are produced typically using a gel concentrate comprising essential oils. It is also possible to add formaldehyde (for preservation) and chlorophyll (preferably <5% by weight), and also further ingredients. Air fresheners are not, however, restricted to living spaces, but may also be intended for autos, cupboards, dishwashers, refrigerators or shoes, and even their use in vacuum cleaners is a possibility. In the household (e.g., in cupboards), for example, in addition to the odour improvers, disinfectants as well are employed, containing preferably compounds such as calcium phosphate, talc, stearin, and essential oils, these products taking the form, for example, of sachets.

The invention is now further described with reference to the following non-limiting examples. These examples are for the purpose of illustration only and it is understood that variations and modifications can be made by one skilled in the art. Example 1: Ethyl 2-acetyl-ll-hydroxy-7,ll-dimethyldodeca-2,6-dienoate

A mixture of 9-hydroxy-5,9-dimethyldec-4-enal (19.8 g, 0.10 mol), ethyl acetoacetate (15.0 g, 0.13 mol) and 2-methyl-2-amino-l-propanol (400 mg, 4.5 mol%) was vigorously shaken until a homogeneous solution was formed, then left to stand in a closed bottle for 30 h. The now biphasic mixture was diluted with MTBE, washed with brine/water 1: 1, sat. aq. NaHC03, water/brine 1: 1 and brine. The organic layer was dried (MgS0 ₄ ), filtered and the filtrate was concentrated. Residual traces of solvent were removed by drying at 0.1 mbar/50°C for lh to yield a yellow oil (31.0 g). The product consists of ethyl 2-acetyl-ll-hydroxy-7,ll- dimethyldodeca-2,6-dienoate as E-/Z-isomers containing some diethyl 2,4-diacetyl- 3-(8-hydroxy-4,8-dimethylnon-3-en-l-yl)pentanedioate.

MS (EI); major isomer: 292 (<1, M ^+, -H ₂ O), 274 (<1), 246 (2), 231 (2), 190 (6), 175 (9), 156 (42), 147 (16), 137 (8), 123 (13), 110 (32), 81 (92), 69 (35), 59 (33), 43 (100).

Odour description: floral, muguet, aldehydic

Example 2: ll-(4-methoxyphenyl)-2,6-dimethylundeca-6,10-dien-2-ol

Potassium t-butylat (1 M in THF, 10.0 mL) was added to a solution of (4- methoxybenzyl)-triphenylphosphonium bromide (4.63 g, 10.0 mmol) in THF (10 mL) at 0 °C. After the red suspension was stirred at 0 °C for 10 min, (E/Z)-9- hydroxy-5,9-dimethyldec-4-enal (1.98 g, 10.0 mmol) in THF (5 ml.) was added at 0 °C, and the mixture was stirred at 25 °C for 2.5 h. After addition of water, the aqueous layer was extracted with MTBE (2x). The combined organic phases were dried (MgS0 ₄ ), filtered and the filtrate was concentrated. The residue was purified by flash chromatography on SiO ₂ (cyclohexane/EtOAc 98:2→ 96:4→ 9: 1) and dried in the "Kugelrohr" oven under HV to yield 1.74 g (57%, purity 99%) of the title compound as a colorless oil. The product consists of a mixture of (6E/Z, 10E/Z)-isomers.

*H NMR (CDCI3, 400 MHz); sum of (6E/Z, 10E/Z) isomers: δ = 7.29-7.20 (m, 2H), 6.98-6.81 (m, 2H), 6.35 (dt, J = 11.6, 1.7 Hz) and 6.33 (d, J = 15.9 Hz) together 1H, 6.08 (dt, J = 15.9, 6.6 Hz) and 6.08 (dt, J = 15.9, 6.7 Hz) together 0.6H, 5.57 (dt, J = 11.6, 7.1 Hz, 0.4H), 5.21-5.14 (m, 1H), 3.80 (s, 1.2H), 3.79 (s, 1.8H), 2.40-2.32 and 2.26-2.10 (2m, together 4H), 2.06-1.96 (m, 2H), 1.70-1.68 (m, 1.2H), 1.61 (s, 1.8H), 1.50-1.38 (m, 4H), 1.22 and 1.21 (br. s, together 1H), 1.20, 1.19, 1.19 and 1.19 (4s, together 6H) ppm.

¹³ C NMR (CDCI3, 100 MHz); mixture of (6E/Z, 10E/Z) isomers: δ = 158.6 (2s), 158.1 (2s), 135.7 (s), 135.6 (s), 135.5 (s), 135.4 (s), 131.0 (d), 131.0 (d), 130.7 (s), 130.7 (s), 130.4 (s), 130.4 (s), 129.9 (4d), 129.3 (d), 129.2 (d), 128.5 (d), 128.5 (d), 128.4 (d), 128.3 (d), 127.0 (2d), 127.0 (2d), 124.7 (d), 124.7 (d), 124.0 (d), 124.0 (d), 113.9 (4d), 113.5 (4d), 70.9 (2s), 70.9 (2s), 55.2 (2q), 55.2 (2q), 43.6 (t), 43.6 (t), 43.5 (t), 43.4 (t), 40.0 (2t), 33.4 (t), 33.2 (t), 32.1 (t), 32.0 (t), 29.2 (2q), 29.2 (2q), 29.2 (2q), 29.2 (2q), 29.1 (t), 28.9 (t), 28.3 (t), 28.2 (t), 27.9 (2t), 23.3 (2q), 22.6 (4t), 16.0 (q), 15.9 (q) ppm.

MS (EI); major isomer: 302 (1, M ^+* ), 284 (1, M ^+* - H ₂ 0), 148 (11), 147 (100), 132 (3), 131 (3), 121 (7), 117 (3), 115 (8), 91 (10), 59 (3), 41 (4).

Odour description: floral, green mimosa, linden-blossom, slightly anisic