CH680852A5 - New 5-methyl-2-(1'-methyl-2'-propenyl)-4-hexene-1-ol - useful perfume ingredient for perfuming soap, shampoo, detergents, etc. - Google Patents

Abstract

5-Methyl-2-(1'-methyl-2'-propenyl)- 4-hexen-1-ol (I) is new, esp. the optically active (-)-(1'S,2S)- and (+)-(1'R,2R) enantiomers (Ia, Ib). USE/ADVANTAGE - (Ia), (Ib) and racemic mixts. of the two are useful perfume ingredients. (Ia) has a floral, rose, natural, very delicate fragrance with a slight trace of cork, slightly rosinol and green, with an overall scent reminiscent of rose and geranium. (Ib) has a floral, rose fragrance with an edge of Rosacene (RTM floral compsn., Firmenich SA), with a more pronounced rose scent than (Ia). (Ia) has a fragrance more like citronellol than (Ib). The prods. are esp. useful as perfume ingredients in perfumes, toilet waters, soap, shower and bath gels, shampoos, cosmetics, body deodourants, air fresheners, detergents, fabric conditioners, household maintenance prods., etc. (claimed). (Ia) and (b) are also useful as starting materials in the prodn. of 4-isopropenyl-2,3-dimethyl-1 -cyclopentanemethanol (IIa) and (4-hydroxymethyl)-1- cyclopentyl) -1-ethanone (IIb) having the formula (II) in which Z is O or CH2.

Description

5

10

15

20

25

30

35

40

45

50

55

CH 680 852 A5

Description

The present invention relates to the field of perfumery. It relates in particular to a new terpene compound, namely 5-methyl-2- (1'-methyl-2'-propenyl) -4-hexen-1-ol and, very particularly, the optically active enantiomers of this compound , of formula or

OH

(-) - (1'S, 2S) (la)

(+) - (1'R, 2R) (Ib)

5-Methyl-2- (1'-methyl-2'-propenyl) -4-hexen-1-ol is a product of the pyrolysis of 3-hydroxymethyl-pinane, which is itself a derivative of pinene. It is precisely as a function of the specific configuration of pinene that 5-methyl-2- (1'-methyl-2'-propenyl) -4-hexen-1-ol is obtained in the form of a racemic mixture. or in the form of optically active enantiomers.

We have discovered that 5-methyl-2- (1'-methyl-2'-propenyl) -4-hexen-1-ol has interesting odoriferous properties and could therefore be used advantageously in the perfume industry. In particular, it turned out that its two enantiomers of formulas (la) or (Ib) had distinct odoriferous properties. This is how (-) - (1'S, 2S) -5-methyl-2- (1'-methyl-2'-pro-penyl) -4-hexen-1-ol has a rosy, natural floral note , very fine, with multiple aspects such as a light cork side, slightly rosinol and green, somewhat reminiscent of rose oxide. It is indeed an odor of the family of pink and geranium notes, with an extremely refined character which evokes the best fractions of the essence of rose. For its part, (+) - (1'R, 2R) -5-methyl-2- (1'-mé-thyl-2'-propényl) -4-hexén-1-ol develops a floral fragrant note, dew, with a Rosacene side (floral composition; origin: Firmenich SA), tea rose more pronounced than the isomer (the) whose odor is however closer to that of citronellol.

As is apparent from the application example presented below, when compared to the citronellol to which they resemble olfactory, the racemic 5-methyl-2- (1'-methyl-2'-propenyl) -4-hexen-1-ol , as well as its two enantiomers, prove to be very different fragrance ingredients, their note having a finer character and much more geranium than that of the fragrant note of citronellol.

In view of their properties, the compounds of the invention can be used for the manufacture of perfumes and perfuming bases or for the perfume of various products such as soaps, cosmetics, shampoos, cleaning products or body deodorants or of ambient air.

The proportions in which the compounds of the invention can develop the desired odorant characteristics can vary within a very wide range of values. Those skilled in the art know from experience that such values depend on the particular effect sought as well, of course, as on the nature of the products which it is desired to flavor. It is also known that these proportions depend on the nature of the other constituents in a given composition when the compounds of formula (la) or (Ib), or the corresponding racemic mixture, are used as ingredients in a perfume base or in a concentrate mixed with other ingredients, common solvents or adjuvants. By other ingredient is meant any compound of natural or synthetic origin whose use in perfumery is common or at least documented. They can be compounds belonging to various chemical classes such as ketones, aldehydes, alcohols or esters in particular. The only limitation in the choice that the perfumer must make from such products is constituted by the olfactory balance of the resulting composition.

In view of the above, the compounds of the invention can, for example, be used in proportions of the order of 5 to 10%, or even 20% or more by weight, relative to the total weight of the composition in which they are incorporated. Lower values are used when perfuming products such as soaps or detergents, for which advantageous effects can already be obtained by the addition of the compounds of the invention in proportions of the order of 0.1 to 0, 5% or even 1% by weight.

2

5

10

15

20

25

30

35

40

45

50

55

60

65

CH 680 852 A5

The present invention also relates to a process for the preparation of an optically active enantiomer of 5-methyl-2- (1'-methyl-2'-propenyl) -4-hexen-1-ol of formula (la), respectively (Ib), characterized in that the (+) - 3-hydroxymethyl-pinane, respectively (-) - 3-hydroxymethyl-pinane, is subjected to pyrolysis, and said enantiomer (la) is separated, respectively (lb ), of the pyrolysis product.

As mentioned above, the above-mentioned optically active isomers of 3-hydroxymethyl-pinane are derivatives of α-pinene, which can be obtained through the formation of 3-formyl-pi-nane according to the method described by W. Himmele and H. Siegel in Tetrahedron Lett. 907-910 and 911-914 (1976). This method is illustrated in the following reaction scheme which relates to the process of the invention:

3

5

10

15

20

25

30

35

40

45

50

55

CH 680 852 A5

DIAGRAM

(-) - a-pinene 1)

CHO

<$ r

(+) - 3-formyI-pinane

2)

OH

(+) - 3-hydroxymethyl-pinane Pyrolysis separation

OH

(-) - (1, S, 2S) -5-methyl-2- (1 '-methyl-2'-propenyl} -4-hexen-1 -ol

{+) - a-pînène 1)

è., ^ CHO

(-) - 3-formyl-pinane i "

(-) - 3-hydroxymethyl-pinane

I Separation pyrolysis

OH

(+) - (1 'R, 2R) -5-methyl-2- (1' -methyl-2'-propenyI) -4-hexen-1-ol

1) cf. Tetrahedron Lett 907-910 (1976)

2) cf. Tetrahedron Lett. 911-914 (1976)

4

5

10

15

20

25

30

35

40

45

50

55

60

65

CH 680 852 A5

It is clear that the use, as starting material in this process, of a-pinene in the form of a racemate makes it possible to obtain 5-methyl-2- (1'-methyl-2'- propenyl) -4-hexen-1-oI also in the form of a racemate.

The pyrolysis reaction of 3-hydroxymethyl-pinane is carried out in accordance with current techniques as described, for example, in US Patents 2,972,638 and US 4,157,451, or also by K.-H. Schulte-EIte and al. in Helv. Chim. Acta 54.1813 (1971). Typically, a solution of the product to be pyrolyzed in an inert solvent is injected at one end of a quartz column previously heated to a predetermined temperature. The operation can be carried out under nitrogen or reduced pressure, and the vapors of the pyrolysate are condensed in a hatch cooled to a very low temperature using an appropriate cooling mixture. The pyrolysis temperature can vary within a wide range of values, for example, between 400 and 700 ° C, preferably from 500 to 600 ° C. According to a preferred embodiment of the process of the invention, this temperature is around 590 ° C. However, this temperature is a function of the length of the quartz column and depends in particular on the value of the pressure applied. Those skilled in the art are able to adapt these parameters, and others such as the pyrolysis time, so as to obtain a good yield of the desired final product.

The condensed pyrolysate is then purified according to the usual techniques such as extraction, fractional distillation or gas chromatography. The desired products, i.e., (-) - (1'S, 2S) -5-methyl-2- (1 '-methyl-2'-propenyl) -4-hexen-1 -ol and (+) - ( 1 'R, 2R) -5-methyl-2- (1' -methyl-2'-propenyl) -4-hexen-1-ol, are thus separated from the pyrolysates obtained from (+) - 3-hydroxymethyl- pinane and (-) - 3-hydroxymethyl-pinane, respectively.

5-methyl-2- (1'-methyl-2'-propenyl) -4-hexen-1-ol and its enantiomers (la) and (Ib) are also compounds useful as starting materials for the preparation of new cyclic compounds, namely, 4-isopropenyl-2,3-dimethyl-1-cyclopentanemethanol and (4-hydroxymethyl-2,3-di-methyl-1-cyclopentyl) -1-ethanone, represented by the formula general in which the symbol Z represents a methylene radical or an oxygen atom. The compounds of formula (II) in which the symbol Z represents a methylene radical are obtained from said starting materials by an intramolecular thermal enene reaction of the type described in particular by H. Strickler et al. in Tetrahedron Lett. 1964. 649 and Helv. 50, 759 (1967). These compounds can then be converted, using an ozonolysis reaction, into the compounds of formula (II) in which the symbol Z represents an oxygen atom.

In this process, the stereochemistry of the starting material determines that of the compound (II), with regard to the relative configuration of the substituent groups in positions 1 and 2 of the ring. For example, as shown in diagram II below, the heat treatment of one of the enantiomers (la) or (Ib) leads to several optically active isomers of the compounds (II), which are all obtained in the pure state using chromatographic separation

5

5

10

15

20

25

30

35

40

45

50

55

CH 680 852 A5

DIAGRAM II

OH

Ozonolysis

OH

Ozonolysis

OH

We have discovered that, like 5-methyl-2- (1'-methyl-2'-propenyl) -4-hexen-1-oI and its enantiomers (la) and (Ib), these isomers optically active compounds (II), represented by the general formulas

6

5

10

15

20

25

30

35

40

45

50

55

60

65

CH 680 852 A5

Z

OH

or

OH

(lia)

(IIb)

in which the symbol Z is defined as before and the wavy lines represent bonds of cyclic configuration eis or trans, as well as their mixtures, have interesting odor properties and can also be used as perfume ingredients in perfume compositions and articles scented. These odorous properties will be described in detail during the preparation examples presented below.

It is clear that other optically active stereoisomeric forms than those presented of 5-methyl-2- (1 '-methyl-2'-propenyl) -4-hexen-1 -ol, 4-isopropenyl-2,3 -dimethyl-1 -cyclopentanemethanol and (4-hydroxymethyl-2,3-dimethyl-1-cyclopentyl) -1-ethanone can be obtained according to the methods described above, by choosing the starting product of appropriate configuration. The preparation examples also describe stereoisomers which have been obtained, for example, using conventional epimerization reactions of other isomers.

The invention will now be described in more detail with the aid of the following preparation examples, in which the temperatures are indicated in degrees centigrade and the abbreviations have the usual meaning in the art, and the application example presented further. The retention times indicated were measured under the following conditions: column 30 m Wax, 70-200 °, 10 ° / min.

Example 1

Preparation of (-ì-M, S.2SÌ-5-methvl-2- (1, -methvl-2 / -oroDénvh-4-hexén-1-ol and of (+ V (1, R.2ffl-5- methvl-2- (1, -methvl-2, -propénvh-4-hexén-1-ol ai f +) - 3-hvdroxvméthvl-pinane

A solution of 20 g of (+) - 3-formyl-pinane [origin: BASF, Ludwigshafen / Rhein (RFA); [a] 20 ° D = + 30.5 °, CHCI3] in 100 ml of absolute Et2Ó was added dropwise, with stirring and argon atmosphere, to 2.5 g of LÌAIH4 and 200 ml of EfeO absolute. After this addition was complete, the reaction mixture was heated at reflux for 1 h. After cooling, it was hydrolyzed according to the method described by V. M. Micovic et al. in J. Org. Chem. 18, 1190 (1953) carefully adding 2.5 ml of water, 2.5 ml of a 15% NaOH solution and another 7.5 ml of water. After filtration and distillation of the residue, 19.0 g of (+) - 3-hydroxymethyl-pinane were obtained.

P. eb. 65 ° / 50 Pa; yield: 94%

[<X] 20 ° D = + 40.6 ° (CHCI3)

IR: 3330 cm "1

NMR (1H, 360 MHz): 1.01 (s, 3H); 1.09 (d, J = 7Hz, 3H); 1.20 (s, 3H); 3.5 (m, 2H) 5ppm. b) M-3-hvdroxvméthvl-Dinane

This compound was prepared in an identical manner to that described in a) but using (-) - 3-formyl-pinane [origin: BASF, Ludwigshafen / Rhein (RFA);

[cc] 20 ° d = -30.7 °, CHCI3] as a starting product. The analytical data for this product were identical to that described in a), except for:

[oc] 20 ° D = —39.8 ° (CHCI3)

c) 44 g of (+) - 3-hydroxymethyl-pinane obtained according to a) were led through a 90 cm quartz column previously heated to 590 ° and maintained at a reduced pressure of 10 Pa.

7

5

10

15

20

25

30

35

40

45

50

55

60

CH 680 852 A5

sat was concentrated in a hatch cooled using a CO2 / acetone mixture. After distillation on residue, 41.7 g of product were obtained (bp 63-75 ° / 10 Pa; yield 94.7%).

This product was subjected to preparative gas chromatography (Carbowax column 15% 5 m) allowing to separate 17.1 g (41%) of (-) - (1'S, 2S) -5-methyl-2- ( 100% pure 1'-methyl-2'-propenyl) -4-hexen-1-ol, the analytical data of which were as follows:

Retention time: 7.4 min

[a] Z0 ° D: —31.2 ° (CHCIs)

IR: 3350, 3090.1645, 910 cm ~ i

NMR (1H, 360 MHz): 1.03 (d, J = 7Hz, 3H); 1.65 and 1.72 (2s wide, 6H); 3.58 (d, J = 6Hz, 2H); 4.8-6.2 (m, 4H) Sppm.

MS: 168 (1, M +), 150 (2), 137 (26), 107 (39), 95 (54), 81 (46), 69 (100), 55 (41), 41 (31).

d) Pyrolysis of (-) - 3-hydroxymethyl-pinane [obtained according to b)], followed by purification, under conditions identical to those described under c), made it possible to obtain the (+) - (1'R, 2R) -5-methyl-2- (1'-methyl-2'-propé-nyl) -4-hexen-1-oi at 100% pure, the analytical data of which were identical to that of the product obtained in c) to l except:

[a] 20 ° D = + 32.4 ° (CHCI3)

Example 2

Preparation of the compounds of formula (liai and (libi in which the symbol Z represents a methylene radical

General method:

These compounds were obtained in parallel with the enantiomers (la) and (Ib), by controlling the conditions of the heat treatment described in example 1 c) and 1 d). Under the conditions described, the product of the heat treatment was, in fact, a mixture of (la), respectively (Ib), with their cyclic derivatives of formula (IIa), respectively (IIb), these cyclic derivatives having then been separated by Preparative gas chromatography as described in Example 1. When the pyrolysis described has been carried out, for example, under a stream of nitrogen, at a temperature of about 490 ° C and in a quartz column of 5 m length (0 10 mm; pyrolysis time of about 51/2 h) a final product was obtained which no longer contained any starting materials, the enantiomers (la) and respectively (ib) having been fully converted into their cyclic derivatives desired.

The following compounds were thus obtained:

1. f + M1S.2S.3R.4Si-4-lsopropénvl-2.3-dimethvl-1-cvclopentanemethanol Retention time: 7.4 min

[aP ° D: + 18.4 ° (CHCIs)

IR: 3350, 3090,1640, 880 cm ~ i

CH NMR, 360 MHz): 0.57 (d, J = 7.2 Hz, 3H); 0.99 (d, J = 6.1 Hz, 3H); 1.47 and 1.99 (2m, 2H); 1.72 (s, 3H); 1.78 (m, 1H); 1.78 (m, 1H); 2.11 (m, 1H); 2.45 (m, 1H); 3.48 (dd, J = 6.5, 10.8 Hz, 1 H); 3.65 (dd, J = 3.6, 10.8 Hz, 1 H); 4.65 and 4.81 (2s, 2H) 5ppm.

NMR ("C): 8.5 (q); 15.6 (q); 23.3 (q); 29.0 (t); 40.2 (d); 40.8 (d); 45.4 (d); 49.8 (d); 67.0 (t); 109.6 (t); 146.0 (s) 5ppm.

SM: 168 (4, M +), 153 (1), 150 (7), 137 (54), 135 (76), 125 (65), 121 (29), 111 (1), 107 (71), 95 (100), 93 (64), 91 (55), 83 (10), 81 (33), 79 (33), 67 (45), 55 (26), 41 (36).

Fragrant note: floral.

2. (+ H1 S.2S.3S.4SV4-lsoproDénvl-2.3-dimethvl-1 -cvclopentanemethanol Retention time: 8.8 min

8

5

10

15

20

25

30

35

40

45

50

55

60

65

CH 680 852 A5

[ocJ20 ° d: + 21.3 ° (CHCIs)

IR (CDCIs): 3620, 3450, 3080.1640 crcH

NMR (1H, 360 MHz): 0.88 (d, J = 6.5Hz, 3H); 1.02 (d, J = 6.5 Hz, 3H); 1.11 (m, 1H); 1.32 (m, 1H); 1.64 and 1.71 (2m, 2H); 1.67 (s, 3H); 1.71 (m, 1H); 2.05 (m, 1H); 3.49 (dd, J = 6.5, 10.8 Hz, 1 H); 3.65 (dd, J = 4.3, 10.8 Hz, 1 H); 4.70 and 4.71 (2s, 2H) 8ppm.

NMR ("C): 16.3 (q); 17.9 (q); 19.1 (q); 33.2 (1); 44.6 (d); 45.9 (d); 48.0 (d); 54.1 (d); 66.6 (t); 110.3 (t); 147.2 (s) Sppm.

SM: 168 (3, M +), 153 (1), 150 (6), 137 (35), 135 (51), 125 (28), 121 (21), 111 (3), 107 (48), 95 (100), 93 (48), 91 (24), 83 (17), 81 (24), 79 (23), 67 (34), 55 (18), 41 (27).

Fragrant note: chemical.

3. (+) - (1 S.2S.3S.4Ri-4-lsoDropénvl-2.3-diméthvl-1 -cvclopentanemethanol

Retention time: 8.1 min

[aJ20 ° D: + 46.6 ° (CHCI3)

IR: 3350, 3080.1640, 880 cm ~ i

NMR (1 H, 360 MHz): 0.73 (d, J = 7.2 Hz, 3H); 1.05 (d, J = 6.5 Hz, 3H); 1.32 (m, 1H); 1.48 (q, J = 11.5 Hz, 1H) and 1.83 (m, 1H); 1.64 (m, 1H); 1.70 (s, 3H); 1.75 (m, 1H); 2.58 (m, 1H); 3.55 (dd, J = 5.0.10.8 Hz, 1H); 3.68 (dd, J = 7.2, 10.8 Hz, 1H); 4.65 and 4.78 (2s, 2H) Sppm.

NMR (13C): 16.2 (q); 21.2 (q); 23.1 (q); 32.3 (t); 42.9 (d); 44.2 (d); 48.2 (d); 49.6 (d); 66.9 (t); 110.1 (t); 146.3 (s) Sppm.

SM: 168 (5, M +), 153 (2), 150 (6), 137 (32), 135 (29), 125 (32), 121 (12), 111 (13), 107 (46), 95 (100), 93 (43), 91 (29), 83 (12), 81 (31), 79 (28), 67 (38), 55 (23), 41 (31).

Fragrant note: floral.

Example 3

Preparation of the compounds of formula filai and (libi in which the symbol 2 represents an oxygen atom

General method:

These compounds were prepared from the corresponding alcohols described in Example 1 according to the following method: a solution of the appropriate alcohol in CH2Cl2, cooled with a CC> 2 / acetone mixture, was saturated with ozone. The excess of the latter was then removed using a current of N2. To reduce the reaction mixture, 30 ml of acetic acid were added and, with stirring at approximately 20 °, 20 g of zinc powder. It was left to react for 1 hour. The reaction mixture was then filtered and washed to neutral with water, NaHCO3 solution and again water. The crude product obtained was distilled in a ball oven.

According to this method, the following compounds were obtained:

1. M-f1S.2R.3S.4S) -f4-hvdroxvmethvl-2.3-dimethvl-1-cvcloDentvl) -1-ethanone

Compound obtained from 4.4 g of (+) - (1S, 2S, 3R, 4S) -4-isopropenyl-2,3-dimethyl-1-cyclopentane-methanol in 100 ml of CH2Cl2. 2.8 g of product were obtained.

P. eb. 150 ° / 50 Pa.

[<x] 20 ° d: + 51.6 ° (CHCIs)

IR: 3450.1710 cm ~ i

NMR (1H, 360 MHz): 0.66 (d, J = 7Hz, 3H); 0.97 (d, J = 7Hz, 3H); 2.14 (s, 3H); 3.02 (m, 1H); 3.48 and 3.63 (2dd, 2H) Sppm.

NMR (13C): 9.6 (q); 14.7 (q); 26.6 (t); 29.8 (q); 41.0 (d); 41.4 (d); 45.0 (d); 56.6 (d); 65.5 (t); 210.0 (s) Sppm.

9

5

10

15

20

25

30

35

40

45

50

55

CH 680 852 A5

SM: 170 (0, M +), 152 (3), 137 (11), 121 (3), 109 (100), 95 (20), 85 (5), 82 (17), 81 (17), 71 (10), 67 (48), 55 (25), 43 (85).

Fragrant note: green, weak.

2. (-W1 R.2S.3S.4SW4-hvdroxvméthvl-2.3-dimethvl-1 -cvclopentvh-1 -ethanone

Compound obtained from 5 g of (+) - (1S, 2S, 3S, 4R) -4-isopropenyl-2,3-dimethyl-1-cyclopentanemé-thanol in 100 ml of CH2Cl2. 4.6 g of product were obtained.

P. eb. 140 ° / 60 Pa.

[a] 20 ° D: —30 ° (CHCIs)

IR: 3450.1710 cm ~ i

NMR ("H, 360 MHz): 0.93 (d, J = 7Hz, 3H); 0.99 (d, J = 7Hz, 3H); 2.16 (s, 3H); 3.12 (m, 1H); 3.60 and 3.71 (2dd, 2H) 8ppm.

NMR (13C): 15.4 (q); 18.4 (q); 30.5 (t); 31.6 (q); 42.6 (d); 44.9 (d); 48.9 (d); 54.3 (d); 65.1 (t); 213.0 (s) Sppm.

SM: 170 (0, M +), 152 (5), 137 (4), 121 (3), 109 (62), 95 (35), 85 (26), 82 (100), 81 (25), 71 (33), 67 (69), 55 (33), 43 (83).

Fragrant note: green, weak.

The following compounds were prepared by epimerization of the two ethanones described above as follows: The appropriate pethanone mixed with 1 ml of a 30% NaOH solution and 50 ml of EtOH was brought to reflux for 1 h. The organic phase was concentrated, etherified and washed with neutrality. The residue was distilled in a ball oven.

3. (+ W1S.2S.3S.4SW4-hvdroxvmethvl-2.3-dimethvl-1-cvclopentvl-1 -ethanone

Prepared by epimerization of Pethanone described above under 2.

P. eb. 130 ° / 10 Pa.

[(xF ° d: + 19.8 ° (CHCIs)

IR: 3450.1710 cm ~ i

OH NMR, 360 MHz): 1.00 (d, J = 7Hz, 6H); 2.15 (s, 3H); 2.50 (m, 1H); 3.49 and 3.68 (2dd, 2H) Sppm.

NMR (13C): 17.1 (q); 17.6 (q); 29.2 (q); 31.4 (1); 44.5 (d); 45.4 (d); 48.4 (d); 58.7 (d); 65.2 (t); 211.6 (s) Sppm.

SM: 170 (0, M +), 152 (2), 137 (17), 121 (10), 109 (100), 95 (25), 85 (11), 82 (15), 81 (22), 71 (8), 67 (62), 55 (32), 43 (82).

Fragrant note: fenugreek, slightly labdanum, chemical (head).

4. (-) - (1 R.2R.3S.4SW4-hvdroxvméthvl-2.3-dimethvl-1 -cvclopentvlVI -ethanone

Obtained by epimerization of Pethanone described above under 1.

P. eb. 150 ° / 20 Pa.

[oc] 2û ° d: -8,6 ° (CHCIs)

IR: 3450.1710 cm-1

OH NMR, 360 MHz): 0.9 (d, J = 7 Hz, 3H); 0.94 (d, J = 7Hz, 3H); 2.16 (s, 3H); 3.48 and 3.65 (2m, 2H) Sppm.

NMR (13C): 15.0 (q); 15.4 (q); 29.2 (q); 30.9 (t); 38.4 (d); 39.9 (d); 47.6 (d); 58.3 (d); 65.5 (1); 211.7 (s) Sppm.

SM: 170 (1, M +), 152 (6), 137 (6), 121 (9), 109 (64), 95 (33), 85 (34), 82 (100), 81 (23), 71 (30), 67 (62), 55 (33), 43 (89).

Fragrant note: slightly green and spicy, blackcurrant.

10

5

10

15

20

25

30

35

40

45

50

55

60

65

CH 680 852 A5

Example 4

Preparation of a perfume composition

A basic perfuming composition of the geranium type was prepared by mixing the following ingredients:

Ingredients:

Parts by weight:

Geranyl formate

300

Geranyl acetate

200

Lemonellyl acetate

100

Geranyl propionate

150

Linaloi

600

Methyl geraniate

300

10% rose oxide *

350

Menthone at 10% *

900

(J-Damascenone 10% *

100

Geraniol

3000

Total

6000

* in dipropylene glycol (DIPG)

To this basic composition was added on the one hand 4000 parts by weight of (-) - (1'S, 2S) -5-methyl-2- (1 '-methyl-2'-propenyl) -4-hexen-1 -ol or (+) - (1 'R, 2R) -5-methyl-2- (1' -methyl-2'-propenyl) -4-hexen-1 -ol to obtain a new composition A and, d on the other hand, 4000 parts by weight of citronellol to obtain a composition B for comparison. In the opinion of the panel of expert perfumers to which these two compositions A and B were subjected for evaluation, composition A had a geranium olfactory character much more pronounced, finer, greener and more mint than that of composition B which exhaled a completely different note, more in the direction of the rose.

Claims (1)

Claims 1.5-Methyl-2- (1'-methyl-2'-propenyl) -4-hexen-1-ol. 2. Optically active enantiomer of 5-methyl-2- (1'-methyl-2'-propenyl) -4-hexen-1-ol of formula (-) - (rS, 2S) (+) - (1'R, 2R) (the) (| b) 3. Use of 5-methyl-2- (1'-methyl-2'-propenyl) -4-hexen-1-ol or one of its enantiomers of formula (la) or (Ib) as fragrance ingredient. 4. Perfuming composition containing as odoriferous ingredient 5-methyl-2- (1'-methyl-2'-pro-penyl) -4-hexen-1-ol or one of its enantiomers of formula (la ) Yes B). 5. Perfumed product containing as odoriferous ingredient 5-methyl-2- (1'-methyl-2'-propenyl) -4-hexen-1-ol or one of its enantiomers of formula (la) or (Ib). 6. As a perfumed product according to claim 5, a perfume or eau de toilette, a soap, a shower or bath gel, a shampoo, a cosmetic preparation, a body or air freshener, a detergent or a textile conditioner, or a cleaning product. 11 5 10 15 20 25 30 35 40 45 50 55 CH 680 852 A5 7. Process for the preparation of an optically active enantiomer of 5-methyl-2- (1'-methyl-2'-propé-nyl) -4-hexen-1-ol of formula (la), respectively (Ib) , characterized in that the (+) - 3-hydroxymethyl-pinane, respectively the (-) - 3-hydroxymethyl-pinane, is subjected to pyrolysis, and the said enantiomer (la), respectively (Ib), is separated from the product pyrolysis. 8. Method according to claim 7, characterized in that the pyrolysis is carried out at a temperature of 500 to 600 ° C, under reduced pressure. 9. Use of 5-methyl- (1'-methyl-2'-propenyl) -4-hexen-1-ol, or one of its enantiomers of formula (la) or (Ib), as product starting material for the preparation of a cyclic compound of formula in which the symbol Z represents a methylene radical, this use consisting in subjecting said starting material to a heat treatment. 10. Use of 5-methyl- (1'-methyl-2'-propenyl) -4-hexen-1-ol, or one of its enantiomers of formula (la) or (Ib), as product starting material for the preparation of a compound of formula in which the symbol Z represents an oxygen atom, characterized in that a compound of formula (II) in which the symbol Z represents a radical is prepared according to claim 9 methylene and subjected to ozonolysis to provide a compound of formula (II) in which the symbol Z represents an oxygen atom. 11. Cyclic compound of formula (II) resulting from the use according to claim 9 or 10. OH (II) 12