JPH02221268A - Production of 2,2-dimethyl-4-phenyltetrahydrofuran and perfumery composition containing the same - Google Patents

Abstract

PURPOSE:To obtain the subject compound useful as a component of a perfumery composition having excellent citrus-like perfume by using 4,4-dimethyl-2-phenyl-4- butanolide as a raw material, reducing the material and treating under acidic condition. CONSTITUTION:The objective compound of formula I can be produced by reducing 4,4-dimethyl-2-phenyl-4-butanolide of formula II with a reducing agent such as LiAlH4 in an ether solvent or with hydrogen under high pressure in a lower alcohol solvent in the presence of a Cu-Cr catalyst to form the compound of formula III and treating the compound in a solvent such toluene at the refluxing temperature under acidic condition with Amberlist 15, etc., (a weakly acidic cation exchange resin), thereby effecting dehydrative cyclization reaction. The objective compound has citrus-like, green-like, citronella-like or pepper-like perfume imaging grapefruit and used singly or in combination with other perfumery components as a component of perfumery, shampoo, etc.

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Field of Application] The present invention is a method for producing 2,2-dimethyl-4-phenyltetrahydrofuran represented by the following formula (I).

The present invention relates to a method for producing 2,2-dimethyl-4-phenyltetrahydrofuran represented by the formula and a fragrance composition containing the same.

[Prior Art and Problems Therewith] Conventionally, several fragrance compounds have been known as substituted tetrahydrofuran derivatives. For example, 2,5-diethyltetrahydrofuran has a very strong grassy odor, and 2-
(3-phenylpropyl)tetrahydrofuran has a sweet fruity aroma reminiscent of honey.
), 2,4-dimethy/L-4-phenyltetrahydrofuran is known to have a very strong fruity aroma reminiscent of rhubarb (European Patent Section 49,5
No. 43).

On the other hand, 2,2-dimethyl-4-phenyltetrahydrofuran (1), which is a furan derivative similar to these, is a compound known in the literature (Pharmaceutical Journal, Vol. 95, p. 710 (1975)), but there is no information on its production method. It had not yet been established, and its properties had not been clarified at all.

[Means for Solving the Problems] Under these circumstances, the present inventors conducted extensive research and found that compound (I) was prepared using 4,4-dimethyl-2-phenyl-4-butanolide represented by the following formula (II) as a raw material. In addition to establishing a method for producing Compound (I), it was also discovered that Compound (I) has an excellent aroma, and the present invention was completed.

That is, the present invention provides 4,4-dimethyl-2-phenyl-
Compound (1) characterized in that 4-butanolide (II) is reduced to 4-methyl-2-phenylpentane-1,4-diol, which is then treated under acidic conditions.
The present invention provides a method for producing compound (I) and a fragrance composition containing compound (I).

In the present invention, compound (I) is produced as follows. That is, according to the following reaction formula, compound (II)
The ring is opened by reducing to give 4-methyl-2-phenylpentane-1,4-diol (m), which is then dehydrated and ring-closed by treatment under acidic conditions to form compound (1). can get.

(II) (III)
(I) Compound (II) in the above reaction
The reduction is carried out using a reducing agent such as lithium aluminum hydride, sodium borohydride, or by high-pressure hydrogenation using a copper-chromium catalyst. Here, the reduction with lithium aluminum hydride is preferably carried out using an ether solvent such as tetrahydrofuran or diethyl ether as a solvent at a temperature below its boiling point.

The reduction with sodium borohydride is preferably carried out using tetrahydrofuran or t-butyl alcohol as a solvent while adding methanol dropwise.

In addition, high-pressure reduction using a copper-chromium catalyst uses lower alcohols such as methanol and ethanol as a solvent.
It is preferable to carry out the reaction at 200 to 300°C, preferably 250 to 270°C, a hydrogen pressure of 200 to 300 atm, and a catalyst amount of 5 to 20% by weight based on compound (II).

Next, in the dehydration ring closure reaction of compound (III), examples of solvents include benzene, toluene, xylene, etc., examples of acids include mineral acids such as sulfuric acid and phosphoric acid, organic acids such as tri-toluenesulfonic acid, and weak acids. This is carried out by using a cation exchange resin or the like and treating at reflux temperature. The amount of acid used here is usually 0.1-10% by weight based on the compound (m) in the case of mineral acids or organic acids, and varies depending on the type of resin in the case of cation exchange resins. 1-2 for Amberlyst 15
0% by weight is preferred.

Compound (II), which is a starting material, can be produced according to the following reaction formula, for example, by the method described in Japanese Patent Application No. 63-265017 previously filed by the present applicant.

(II) [Action and effect of the invention] 2.2-dimethyl-4-phenyltetrahydrofuran (
I) has a citrus-like, green-like, citronella-like, and wildflower-like aroma reminiscent of grapefruit,
A perfume composition can be prepared using this alone or in combination with other perfume ingredients. That is, the compound (
I) can impart a fresh citrus-like aroma by adding 1 to 20% by weight as a compounding material to regular fragrance ingredients, so it can be used in perfumes, soaps, shampoos, room air fresheners, detergents, etc. It can be widely used in materials that require fragrance.

[Example] The present invention will be described in more detail with reference to Examples below, but the present invention is not limited thereto.

Example 1 (a) Reduction with lithium aluminum hydride 24 g (0.63 mol) of lithium aluminum hydride was dissolved in ether 500Tnf1, and 4,4-dimethyl-2
-Phenyl-4-butanolide (II) 120g (0,
63 moles), ether 240 m1! A mixed solution of 120 ml of tetrahydrofuran was added dropwise over 1 hour while cooling with water. Thereafter, the mixture was gently heated under reflux for 1 hour.

After the reaction was completed, the temperature was returned to room temperature, and 24 ml of water, 24 ml of 15% aqueous sodium hydroxide solution and water were added. 2 m1i were added sequentially to decompose the excess lithium aluminum hydride.

After removing the generated white precipitate by suction filtration, the filtrate was distilled under reduced pressure to obtain 87 g (0,4
5 mol) was obtained (yield 72%).

(b) Reduction with sodium borohydride 120 g of 4.4-dimethyl-2-phenyl-4-butanolide (II)
(0,63 mol), sodium borohydride 60 g (1
, 59 mol) and tetrahydrofuran In was heated to reflux, and 500 mM of methanol was added dropwise over 1 hour. After continuing to reflux for about 1 hour, water was added to stop the reaction, the solvent was distilled off, and the residue was extracted with dichloromethane. After drying with anhydrous sodium sulfate, distillation was performed to obtain 85 g (0.44 mol) of diol compound (II).
was obtained (yield 70%).

(C) High pressure reduction using copper-chromium catalyst 4.4-dimethyl-2-phenyl-4-butanolide (I
I) 120 g (0.63 mol), 81 g of methanol, and 20 g of copper-chromium catalyst (8 volatile) were placed in an autoclave, and after replacing the inside with hydrogen, the hydrogen pressure was 80 atm and the temperature was 2
About 1 hour at 30℃, then hydrogen pressure of 250 atm and temperature of 25℃.
The reaction was carried out at 0°C for 7 hours. After cooling, the pressure was returned to normal, and the catalyst was filtered and distilled under reduced pressure to obtain 79 g of diol (0.41
mol) was obtained (yield 65%).

Diol body (m) 87g (0.45 mol), weakly acidic cation exchange resin Amberlyst 15 (Amberlys
t15) A mixed solution of 4.3 g and 100 ml of toluene was heated under reflux for 4 hours to perform an azeotropic dehydration reaction. After the reaction was completed, the temperature was returned to room temperature, and the amberlyst was filtered off. This filtrate was distilled under reduced pressure to obtain 73 g (0,4
2 mol) was obtained (yield 92.5% based on the charged diol compound (II)).

Boiling point: 100℃/? mm1g Elemental analysis (as C■H1・O): Analysis value: C81,59,H9,21 Theoretical value: C81,7? , H9,15M5 (relative strength): 176 (M”, 15), 161 (47), 146 (
32), 131 (10G), 117 (24), 91
(25), 83(12), 43(75), 28(
34) IR(IIeat, am-”): 2974
, 149? , 145g, 1371.1272.11
58.1053°753,699 Deuterium H-NMR (CDCQs solvent, TMS internal standard,
δ) Near, 3-7.1 (58, +a), 4.17 (I
H, t, 8), 3.75 (IH, t, 8).

3.48 (IH, m), 2.16 (IH, dd, 8.
12), 1.83 (IH, dd.

11.12), 1.36(3H,s), 1.28(
3H,s)"C-NMR: 141.8(S), 128.5(2c,d), 12
7.2 (2c, d), 126.4 (d), 81.2
(s), 73.5 (t), 47.0 (t), 45
．． 5(d).

28.8(q), 28.3(q) Example 2 Leh Fruit Taibe A (parts by weight) Orange oil Vera citral Mylac aldehyde l) Frutate 1) Citronellyl isobutylacetyralyl acetate Sagetone v1 Sandal Mysore core 4) 3-Cyclopenten-1-yl)-2-buten-1-O Application Å By adding 200 parts by weight of Compound (I) to the above-mentioned blended flavor, a grapefruit type blended flavor with a fresher and more natural feel was created. was gotten.

Note 1) Manufactured by IFF, 4-(4-methyl-3-penten-1-yl)3-cyclohexene-1-carbaldehyde 2) Manufactured by Kao Corporation, ethyltricyclo[5,2,1,
0''.6] Decane-2-carboxylate 3) Spiro[bornane-3,l゛-cyclopent-2-one] manufactured by Kao Corporation

Claims (2)

[Claims] (1) 4,4-dimethyl-2-phenyl-4-butanolide represented by the following formula (II) ▲Mathematical formulas, chemical formulas, tables, etc.▼(II) is reduced to 4-methyl-2-phenylpentane. 2,2-dimethyl-4 represented by the following formula (I) ▲ There are mathematical formulas, chemical formulas, tables, etc. -Production method of phenyltetrahydrofuran. (2) A fragrance composition containing 2,2-dimethyl-4-phenyltetrahydrofuran represented by the following formula (I) ▲Mathematical formula, chemical formula, table, etc.▼(I).