FLAVORANT AND FRAGRANCE FURAN- 2 (5H) -ONE COMPOUNDS

This invention relates to flavorants and fragrances and compounds for use therein.

A method of providing a flavour or a fragrance to a composition, comprising the addition thereto of a compound of the formula I

in which R ¹ and R ³ are independently selected from at least one of H, C ₁ -C ₁₀ straight chain alkyl or branched chain alkyl, and in which R ² and R ⁴ are independently selected from at least one of C ₁ -C ₁₀ straight chain alkyl or branched chain alkyl.

According to certain illustrative embodiments, the compound of Formula I include those wherein R ¹ , R ² , R ³ , and R ⁴ are represented by the following:

R ¹ is C ₁ -C ₁₀ straight or branched chain alkyl; R ² is C ₁ -C ₁₀ straight or branched chain alkyl or R ¹ and R ² together form a 3-8- membered ring;

R ³ is H, C ₁ -C ₁₀ straight or branched chain alkyl;

R ⁴ is C ₁ -C ₁₀ straight or branched chain alkyl.

According to further illustrative embodiments, the compound of Formula I include those wherein R ¹ , R ² , R ³ , and R ⁴ are represented by the following: R ¹ is at least one of methyl or ethyl;

R ² is at least one C ₁ -C ₁₀ straight or branched chain alkyl or R ¹ and R ² together form a 3-8-membered ring; R ³ is at least one of H, methyl, or ethyl;

R ⁴ is at least one of methyl, ethyl, propyl, butyl, pentyl, isopropyl, isobutyl or isopentyl.

The compounds of Formula (I) may comprise one or more chiral centres and as such may exist as a mixture of stereoisomers. Alternatively, the mixture of stereoisomers may be resolved as isomerically pure forms. As resolving stereoisomers adds to the complexity of manufacture and purification of these compounds, it is simply more economical to use the compounds as mixtures of their stereoisomers. If it is desired to prepare individual stereoisomers, this may be achieved according to methods known in the art, for example, preparative HPLC and GC or by stereoselective syntheses.

While certain of the compounds are known, for example, 3,5,5-trimethyl-

2(5H)-furanone is known in green tea (see, for example, Shimoda et al, J.Agr.Food.Chem.(1995) 43(6), 1621-5), others are novel compounds not previously disclosed. Thus, in other aspects, provided are compounds of Formula (I) selected from those in which the groups R ¹ , R ² , R ³ and R ⁴ in illustrative individual compounds are selected as follows:

R ¹ R ² R ³ R ⁴

Methyl heptyl hydrogen methyl

Methyl Octyl hydrogen methyl Methyl Nonyl hydrogen methyl

Methyl Decyl hydrogen methyl

Methyl isopentyl hydrogen methyl

Ethyl Ethyl hydrogen methyl

Ethyl Propyl hydrogen methyl Ethyl Pentyl hydrogen methyl

Ethyl Hexyl hydrogen methyl

Ethyl Heptyl hydrogen methyl

Ethyl Octyl hydrogen methyl

Ethyl Nonyl hydrogen methyl Ethyl Decyl hydrogen methyl

3-membered ring with R2 hydrogen methyl

4-membered ring with R2 hydrogen methyl 5-membered ring with R2 hydrogen methyl 7- membered ring with R2 hydrogen methyl

Methyl Hexyl methyl methyl Methyl Heptyl methyl methyl Methyl Octyl methyl methyl Methyl Nonyl methyl methyl Methyl Decyl methyl methyl Methyl Methyl hydrogen Pentyl Methyl Methyl hydrogen Hexyl Methyl Methyl hydrogen Heptyl Methyl Methyl hydrogen Octyl Methyl Methyl hydrogen Nonyl Methyl Methyl hydrogen Decyl

The compounds may be obtained from natural sources or synthesised by known methods, for example, by that described by Iwahama et al in Chem. Comm., 2000, 613-614 and Yates in Can. J. Chem., 1987, 68 (8), 1695, both of which are incorporated herein by reference in their entireties.

The compounds of Formula I are useful for the provision of flavours in compositions that are to be taken orally. Thus, in certain embodiments, a composition for oral reception or ingestion is provided, the composition comprising a flavorant comprising a compound of Formula I as hereinabove described. The composition to which the compound of Formula I is added may be any such composition. For example, it may be a foodstuff, baked goods, confectionery, including chewing gum and hard candy, a beverage, a tobacco product, a dental preparation, such as a toothpaste, a tooth gel or a mouthwash, or a solid, liquid or sprayable medicinal preparation. Therefore, also provided is a flavoured product that is orally receivable or ingestible, in which the flavoured product comprises a flavorant that is a compound according to Formula I above.

The compounds of Formula I are also useful as fragrances. They may be used in fine fragrances, such as perfumes, or as functional fragrances in any of the wide range of products that contain fragrance, for example, detergents, soaps and other personal products, such as creams and lotions, body care products, cosmetic products, household cleaning agents and preparations, polishes, consumer healthcare products, air fresheners and the like. Therefore, further provided is a fragranced product, in which the fragranced product comprises a fragrance that is a compound according to Formula I above.

The phrases "a compound of Formula I" and "a compound according to

Formula I" refer to embodiments in which one such compound, or a mixture or combination of more than one such compound, is used.

The compounds of Formula I may be added to products in the conventional manner using standard equipment and in generally art-recognised proportions. These will naturally vary, depending on the use and extent of flavour or fragrance desired. It is also possible to exceed the generally-recognised proportions, should a particular effect should be desired. In addition, such products may also incorporate the particular raw materials known to the art for use in that particular product, again in the usual proportions.

The method, compounds, flavoured compositions, and fragranced compositions are further described with reference to the following non-limiting, illustrative examples. 3,5,5-trimethylfuran-2(5H)-one

5-ethyl-3,5-dimethylfuran-2(5H)-one

5-butyl-3,5-dimethylfuran-2(5H)-one

5-hexyl-3,5-dimethylfuran-2(5H)-one

5-isopentyl-3,5-dimethylfuran-2(5H)-one 3,5-dimethyl-5-octylfuran-2(5H)-one

5-decyl-3,5-dimethylfuran-2(5H)-one

3-ethyl-5,5-dimethylfuran-2(5H)-one

3,4,5,5-te1xamethylfuran-2(5H)-one 3-butyl-5,5-dimethylfuran-2(5H)-one 3-hexyl-5,5-dimethylfuran-2(5H)-one 5,5-diethyl-3-methylfuran-2(5H)-one 3-methyl- 1 -oxaspiro[4.5]dec-3-en-2-one 3-methyl-l-Oxaspiro[4.4]non-3-en-2-one

Certain exemplary compounds and their characteristics are shown below, followed by the method of preparation:

Example

Taste description (at lOppm in water): 1 nutty, brown, condensed milk, nutmeat, slight fatty mouthfeel, and added slight astringent aftertaste.

Taste description (at lppm in water): Mushroom, musty, oily mouthfeel, greasy, and added astringent aftertaste.

Odour Description: linear, celery leaves, clean, linear, natural, fenugreek.

Odour Description: slightly minty, green, fruity, buttery.

Odour Description: buttery, creamy, celery, fatty.

Methods for the general preparation of unsaturated lactones from α-hydroxy- γ-lactones are described in T. Iwahama, S. Sakaguchi, Y. Ishii, Chem. Comm., 2000, 613-614 and P. Yates, Can. J. Chem., 1987, 68 (S), 1695.

Example 1: 3,5,5-trimethylfuran-2(5H)-one

A) Preparation of dihydro-3-hydroxy-3,5,5-trimethylfuran-2(3H)-one

In a 50OmL flask, fitted with magnetic stirrer, reflux condenser, 3.26g of N- hydroxyphtalimide, 120g of isopropanol, 0.05g of Cobalt (II) acetate (4H ₂ O) and

0.7 Ig of cobalt (IιI)acetylacetonate and 33mL of acetonitrile were added. The flask was evacuated and placed under an oxygen atmosphere (balloon). 2Og of methyl methacrylate were added at room temperature and the greenish solution was heated to

7O ⁰ C and stirred at 70°C for 6h and for 16h (over night) at RT (under nitrogen), while it became brownish.

The mixture was concentrated and purified by column chromatography and crystallization from MTBE/Hexane, yielding 5.63g white crystals (19.5% yield).

¹ H NMR (300 MHz; CDCl ₃ ) δ: 2.75 (s, IH) 2.32 (d, IH), 2.10 (d, IH), 1.53 (d, 6H), 1.46 (s, 3H)

¹³ C NMR (300 MHz; CDCl ₃ ) δ: 178.49, 82.21, 48.45, 29.13, 28.98, 26.30 mp: 66-68 ⁰ C

B) Preparation of 3,5,5-trimethylfuran-2(5H)-one

In a 10OmL flask, fitted with magnetic stirrer, reflux condenser, 5.0Og of dihydro-3- hydroxy-3,5,5-trimethylfuran-2(3H)-one and 29.2g of hydrobromic acid (48% in water) were added and heated at reflux (135 ⁰ C oilbath) for 4h. The mixture was poured on ice and extracted with MTBE. The organic layer was washed with brine, dried over magnesium sulfate and concentrated. The crude product was crystallized from MTBE and washed with hexane, yielding 1.75g white crystals (40% yield).

¹ H NMR (300 MHz; CDCl ₃ ) δ: 7.00 (dd, IH), 1.89 (d, 3H), 1.44 (s, 6H)

¹³ C NMR (300 MHz; CDCl ₃ ) δ: 173.63, 153.92, 128.18, 84.06, 25.63, 10.41 MS: 126 (M+), 111, 83, 67, 55, 43, 39 IR: 3462.2, 3087.9, 2983.0, 2932.1, 1744.3, 1665.7 mp: 54-55°C

Example 2: 5-butyl-3.5-dimethylfuran-2(5H)-one

5-butyl-3,5-dimethylfuran-2(5H)-one was prepared according to the general procedure in Example 1, using 2-hexanol and methyl methacrylate. ¹ H NMR (300 MHz; CDCl ₃ ) δ: 6.9 (dd, IH), 1.90 (d, 3H), 1.8-1.6 (m, 2H), 1.41 (s, 3H), 1.3-1.2 (m, 4H), 0.9 (t, 3H)

¹³ C NMR (300 MHz; CDCl ₃ ) δ: 173.83, 153.06, 128.75, 86.47, 38.36, 24.14, 22.73, 13.83, 10.47

MS: 168 (M+), 153, 140, 125, I I I, 91, 83, 69, 55, 43

Example 3: 3-ethyl-4,5.5-trimethylfuran-2(5H)-one

In a round bottom flask, 13.8g of potassium carbonate (O.lmol), 18.8g of Diethyl ethylmalonate (0.1 mol) and 10.2g of 3-Hydroxy-3-methyl-2-butanone (O.lmol) were added and heated for 6h at 180°C. MTBE was added to the reaction mixture, the reaction mixture was filtered and concentrated. The crude mixture was distilled by Kugelrohr distillation, yielding 10.0g (64% yield).

¹ H NMR (200 MHz; CDCl ₃ ) δ: 2.3 (dd, 2H), 1.9 (s, 3H), 1.4 (s, 6H), 1.1 (t, 3H)

Example 4: 5-ethyl-4,5-dimethyl-3-propylfuran-2(5H)-one

5-ethyl-4,5-dimethyl-3-propylfuran-2(5H)-one was prepared according to example 3, using 3-Hydroxy-3-methyl-2-pentanone and Diethyl propylmalonate.

¹ H NMR (200 MHz; CDCl ₃ ) δ: 2.2 (t, 2H), 2.0-1.8 (m, 2H), 1.9 (s, 3H), 1.7-1.4 (m, 4H), 1.4 (s, 3H), 0.9 (t, 3H), 0.8 (t, 3H)

Example 5: 4,5.5-Mmethyl-3-pentylfuran-2(5H)-one

4,5,5-trimethyl-3-pentylfuran-2(5H)-one was prepared according to example 3, using 3-Hydroxy-3-methyl-2-butanone and Diethyl pentylmalonate. ¹ H NMR (200 MHz; CDCl ₃ ) δ: 2.2 (t, 2H), 1.9 (s, 3H), 1.6-1.4 (m, 2H), 1.4 (s, 3H), 1.4-1.2 (m, 4H), 0.9 (t, 3H)

Example 6: Hazelnut

1 Oppm of 3,5,5-trimethylftjran-2(5H)-one (Example 1) was added to a beverage base (1Og sugar, 9Og water) containing 0.65% by weight of hazelnut fluid extract (a hydroalcoholic extract (ethanol and propylene glycol) of hazelnut, corylus Americana, ex Chart). The resulting composition showed a fuller, toasted, slight roasted, brown, slightly creamy, definitely nutty, slight macadamia nut aroma, while the hazelnut extract alone was slightly sweet, woody, astringent and rather plain at that level.

The phrase "at least one of as used herein means one member of a given group or listing of members, or combinations of two or more members of the given group of members. The phrase "at least one of does not require one of each member of a given group of members.

While the method, compound, flavoured composition, and fragranced composition have been described above in connection with certain illustrative embodiments, it is to be understood that other similar embodiments may be used or modifications and additions may be made to the described embodiments.

Furthermore, all embodiments disclosed are not necessarily in the alternative, as various embodiments may be combined to provide the desired characteristics. Variations can be made by one having ordinary skill in the art without departing from the spirit and scope of the invention. Therefore, method, compound, flavoured composition, and fragranced composition should not be limited to any single

embodiment, but rather construed in breadth and scope in accordance with the recitation of the attached claims.