Perfume Compositions and Process for Preparing Same

Fragrance compounds with a naturally green odor are highly esteemed in the perfume industry. Such fragrance compounds are mostly natural in origin and thus a sufficient supply is not always available. Moreover, the quality of these naturally occurring fragrance compounds tend to vary. Accordingly a growing demand exists for synthetic fragrance compounds which can replace these natural compounds.

It has now been found that new 1,5-alkadienols and esters derived therefrom, having the general structural formula: ##STR1## wherein R.sub.1 is an alkyl group having from 1 to 4 carbon atoms and R.sub.2 is selected from the group consisting of hydrogen (dienols), formyl radicals and alkyl carbonyl radicals, the alkyl portion of which has from 1 or 2 carbon atoms (dienol esters), are valuable fragrance compounds.

Of these novel compounds, those where R.sub.1 is a straight chain (unbranched) alkyl group having from 1 to 3 carbon atoms are preferred. Especially important among the compounds of formula I are the alcohols (R.sub.2 .dbd. H) and acetates (R.sub.2 .dbd. COCH.sub.3). One of the novel compounds of the present invention is 1,5-nonadien-4-ol. This compound has a green, slightly earthy and mushroom-like odor. Another specific compound of the present invention is 1,5-undecadien 4-ol and the corresponding acetate; both have a green and slightly fatty odor. The odor of this acetate is particularly suggestive of galbanum.

According to the present invention the 1,5-alkadien-4-ols may be prepared by reacting an .alpha.,.beta.-unsaturated aldehyde having the structural formula

and wherein R.sub.1 has the same meaning as R.sub.1 in formula I above, with allyl-magnesium chloride

the reaction scheme is as follows: ##STR2## The alcohols thus obtained may be converted into esters in accordance with esterification procedures well known in the art.

The compounds according to the invention are strong and stable fragrance compounds with a long lasting odor. As such, they may be incorporated successfully in perfume compositions. The term "perfume composition" as used herein means a mixture of organic compounds, such as aldehydes, ketones, alcohols, carboxylic acids, esters, nitriles, essential oils, etc., which is used, as such or after dilution with a suitable solvent or in combination with a solid substrate, to impart a desired odor to the skin or to products such as air freshener sprays, deodorants, soap, detergents, cosmetics, etc.. According to the present invention, the amount of the novel 1,5-alkadien derivative to be used in said perfume compositions or products may vary widely, depending upon the specific composition, the type and quantity of the other components of the composition and the desired odor effect. Some of the compounds of the invention have such strong odors that they will have a clearly perceptible positive effect upon a perfume composition when added in quantities as low as about 100 parts per million. However, in some cases quantities of up to about 15% by weight may be used in perfume compositions to achieve specific odors. These quantities apply to pure perfume compositions. On dilution with a solvent or a substrate, or on application in a product to be perfumed, these quantities are proportionally lower, depending on the quantity of perfume composition that is used.

A mixture of 300 ml of tetrahydrofuran, 21 g of magnesium, 0.07 g of iodine and 2 g of allyl chloride in a nitrogen atmosphere is carefully heated to 35.degree. C under constant stirring. When the reaction has started, a mixture of 700 ml of tetrahydrofuran, 58.2 g of allyl chloride and 100.8 g of 2-octenal is carefully added in 3 hours. During this addition the temperature is kept at 30.degree.-35.degree. C, if necessary by cooling with a waterbath. The stirring of the reaction mixture at this temperature is continued for another 1.5 hours. After cooling the reaction mixture to room temperature, it is poured in a mixture of 80 g of acetic acid, 800 g of ice and 200 ml of toluene.

The total mixture is stirred vigorously, the water layer is separated and extracted with 100 ml of toluene. The combined organic layers are washed with water, 5% soda-solution and again with water. The solvent is evaporated and the residue is distilled under reduced pressure. 80.6 g of 1,5-undecadien-4-ol is obtained (64%); b.p. 75.degree.-78.degree. C/2 Torr; n.sub.20.sup.D = 1.4568.

0.1 Mole of allyl-magnesium chloride, prepared from 0.1 mole of allyl chloride and magnesium in excess, is added carefully to a solution of 0.1 mole of 2-hexenal in 50 ml of tetrahydrofuran at 5.degree. C. The reaction mixture is subsequently stirred at room temperature for 1 hour. The reaction mixture is hydrolyzed by pouring it into a mixture of ice and acetic acid in excess.

The whole mixture is subsequently extracted with toluene and the solution in toluene is washed until neutral with 5% soda-solution. The solvent is evaporated and the residue distilled under reduced pressure. 1,5-Nonadien-4-ol is obtained in 65% yield; b.p. 77.degree. C/10 Torr; n.sub.20.sup.D = 1.4548.

36 g of 1,5-undecadien-4-ol is stirred and heated to reflux with 32.6 g of acetic acid anhydride for 1 hour. The excess anhydride and the resulting acetic acid are removed by distillation under reduced pressure. The residue is fractionated. Yield: 33.8 g (76%) 1,5-undecadien-4-yl acetate; b.p. 70.degree.-80.degree. C/2 Torr; n.sub.20.sup.D = 1.4468. 1,5-Nonadien-4-yl acetate was prepared in a similar way; yield: 75%; b.p. 85.degree. C/10 Torr; n.sub.22.sup.D = 1.4403.

A perfume composition of the lavender-type was prepared according to the following recipe:

A perfume composition of the "Men's cologne" type was prepared according to the following recipe: