Cycloalkylidene derivatives and fragrance composition

Cycloalkylidene derivatives of the general formulae Ia to Ic ##STR1## where the dashed line is a possible additional chemical bond, the radicals R.sup.1 are identical or different C.sub.1 -C.sub.4 -alkenyl groups, R.sup.2 and R.sup.3 are each methyl or ethyl, R.sup.4 is hydrogen or one of the radicals R.sup.1, X is oxygen, methylene or a chemical bond, m is from 0 to 3 or, when X is methylene, is from 1 to 3, or, when X is methylene and R.sup.1 is methyl, is from 2 to 3 and n is from 0 to 3, are used as fragrance materials.

The present invention relates to cycloalkylidene derivatives of the general 
formulae Ia to Ic 
##STR2## 
where the dashed line is a possible additional chemical bond, the radicals 
R.sup.1 are identical or different C.sub.1 -C.sub.4 -alkyl or C.sub.2 
-C.sub.4 -alkenyl groups, R.sup.2 and R.sup.3 are each methyl or ethyl, 
R.sup.4 is hydrogen or one of the radicals R.sup.1, X is oxygen, methylene 
or a chemical bond, m is from 0 to 3 or, when X is methylene, is from 1 to 
3, or, when X is methylene and R.sup.1 is methyl, is from 2 to 3 and n is 
from 0 to 3. 
The present invention furthermore relates to processes for the preparation 
of the cycloalkylidene derivatives Ia to Ic and their use as fragance 
materials in cosmetic preparations and household and industrial care 
agents. 
Cycloalkylidene derivatives of the type Ia having the structural unit of an 
unsubstituted cyclohexyl ring are known from the work of Cresson (Bull. 
Soc. Chim. France 10 (1964), 2618-2628). It has been found that the 
compound in which R.sup.2 and R.sup.3 are each methyl has a fresh, green, 
herbaceous note. 
Spirocyclic ethers having the basic structure Ic have been disclosed as 
fragrance materials in U.S. Pat. Nos. 4,010,286, 4,186,103, 4,192,782 and 
4,240,447; in contrast to Ic, in the said ethers R.sup.2 and R.sup.3 are 
each hydrogen and the ethers carry a methyl or methylene group in the 
4-position of the dehydropyran ring. 
It is an object of the present invention to provide novel compounds having 
novel fragance properties. 
We have found that this object is achieved by the compounds Ia to Ic 
defined at the outset. We have furthermore found processes for their 
preparation, their use as fragrance materials and formulations of scent 
compositions which contain them. 
Preferred compounds Ia are those in which X is a chemical bond or methylene 
and R.sup.1 is an alkyl substituent in the 2- and 4- position. 
Examples of such compounds are: 
4-cyclopentylidene-2,2-dimethylbutanal, 
4-[2,4,4'-trimethylcyclopentylidene]-2,2-dimethylbutanal, 
4-[4-isopropylcyclohexylidene]-2,2-dimethylbutanal. 
The compounds Ia are obtained by converting a cyclic ketone (II) with a 
vinylmagnesium halide into the vinylcarbinol (III), reacting III with 
phosgene or thionyl chloride in a conventional manner to give IV and 
reacting the latter with an aldehyde V: 
##STR3## 
The reaction of cyclic ketones with a vinylmagnesium halide is known per se 
(Houben-Weyl, Methoden der organischen Chemie, Volume XIII/2a (1973), 
pages 47-527), so that detailed information in this respect is 
unnecessary. 
The vinylcarbinols III can be converted into the compounds IV by reaction 
with a chlorinating reagent, preferably phosgene or thionyl chloride, at 
from -80.degree. to 150.degree. C., preferably from -20.degree. to 
20.degree. C. The reactions can be carried out in the absence of a solvent 
or in a solvent. Suitable solvents are ethers, such as diethyl ether, 
esters, such as ethyl acetate, aliphatic and aromatic hydrocarbons, such 
as hexane or toluene, amides, such as dimethylformamide, sulfoxides, such 
as dimethy sulfoxide or mixtures of these solvents. 
Finally, for the preparation of the cycloalkylidenealkanals, the allyl 
chlorides (IV) can be reacted with a 1-fold to 2-fold, preferably 1-fold 
to 1.5-fold, excess of aldehdye V. The reaction can advantageously be 
carried out in a basic medium, preferably in a two-phase system consisting 
of an aqueous alkali metal hydroxide solution and toluene, with the aid of 
a phase transfer catalyst. Suitable phase transfer catalysts are 
quaternary ammonium salts, such as tetrabutylammonium iodide. 
Preferred compounds Ib are those having a cyclohexyl radical which carries 
either no radicals or identical or different radicals R.sup.1 in the 
positions 2, 3, 4 or 6. Examples of such compounds are: 
4-[cyclohexylidene]-2,2-dimethylbutanol, 
4-[3,3-dimethylcyclohexylidene]-2,2-dimethylbutanol, 
5-[2,5,6-trimethylcyclohex-2-enylidene]-3,3-dimethylpentan-2-ol, 
4-[4-isopropylcyclohexylidene]-2,2-dimethylbutanol and 
5-[4-isopropylcyclohexylidene]-3,3-dimethylpentan-2-ol. 
The compounds Ib can be obtained by reducing the formyl group of the 
cycloalkylidenealkanals Ia, preferably with a complex metal hydride, such 
as lithium aluminum hydride or sodium borohydride, or by reaction with an 
alkyl- or vinylmagnesium halide. 
The reduction with the metal hydrides can be carried out in an alcohol, 
such as methanol, ethanol or tert-butanol, at from 0.degree. to 50.degree. 
C., preferably 25.degree. C. The reaction of the cycloalkylidenealkanals 
Ia with the Grignard compounds is effected by methods generally known from 
the literature, so that further information in this respect is unnecessary 
(Houben-Weyl, Methoden der Organischen Chemie, Volume XIII/2a (1973), 
pages 47-527). 
Those spirocyclic ethers (Ic) which are composed of two six-membered rings 
and carry one of the radicals R.sup.1 in the 7- or 8-position show the 
most interesting fragrance notes. Examples of such compounds are: 
3,3'-dimethyl-8-isopropyl-1-oxaspiro[5.5]undecane, 
3,3'-dimethyl-7,7'-dimethyl-1-oxaspiro[5.5]undecane, 
2-methyl-3,3'-dimethyl-7,7'-dimethyl-1-oxaspiro[5.5]-undecane, 
2-vinyl-3,3'-dimethyl-7,7'-dimethyl-1-oxaspiro[5.5]-undecane, 
2-methyl-3,3'-dimethyl-7,7'-dimethyl-1-oxaspiro[5.5]-undecane. 
The compounds Ic are preferably obtained by cyclization of the 
corresponding cycloalkylidenealkanols Ib in the presence of acidic 
catalysts. 
The reaction can be carried out at from -80.degree. to 100.degree. C., 
preferably from -20.degree. to 50.degree. C., in the absence of a solvent 
or in an inert solvent. Suitable solvents are hydrocarbons, such as 
toluene, chlorohydrocarbons, such as methylene chloride and chlorobenzene, 
and ethers, such as tetrahydrofuran and methyl tert-butyl ether. Suitable 
acidic catalysts are inorganic and organic acids, such as sulfuric acid, 
phosphoric acid, hydrochloric acid, acetic acid, oxalic acid and 
p-toluenesulfonic acid, acidic ion exchangers and Lewis acids, such as 
zinc chloride and boron trifluoride. 
The novel compounds Ia and Ib have fresh and floral notes, whereas the 
spirocyclic ethers have a pronounced sensual fragrance. They are used 
alone or preferably with other fragrance materials in the conventional 
combinations for the preparation of perfumes, for perfuming, i.e. for 
imparting fragrance properties to, or improving or modifying the fragrance 
properties of, cosmetic products and detergent compositions for household 
and industrial use.

EXAMPLES 1 TO 6 
Preparation of the Compounds Ia 
A solution of 4.5 mol of vinylmagnesium chloride in 3 l of tetrahydrofuran 
was added to 3.5 mol of a cyclic ketone (II) at 25.degree. C. in the 
course of 2 hours. After the mixture had been stirred for 12 hours, the 
Grignard compound was hydrolyzed with 450 ml of water, after which the 
mixture was extracted with methyl tertbutyl ether. Working up in the 
conventional manner gave the vinylcarbinol III. 
2.2 mol of phosgene were passed into 2.0 mol of the vinylcarbinol (III), 
dissolved in a mixture of 600 ml of toluene and 180 ml of 
dimethylformamide, at 0.degree. C. in the course of 4 hours. The reaction 
mixture was then stirred for a further hour. For working up, the mixture 
was washed thoroughly with twice 1 l of water and neutralized with 
NaHCO.sub.3 solution and the organic phase was evaporated down. This 
solution was used directly in the subsequent reaction. 
2.2 mol of isobutyraldehyde (V) and 1.65 mol of allyl chloride IV, 
dissolved in 600 ml of toluene/dimethylformamide, were added dropwise to a 
solution of 27 mmol of tetrabutylammonium iodide in 25% strength sodium 
hydroxide solution at 50.degree. C. Stirring was then carried out for 16 
hours at 50.degree. C. and for 4 hours at 70.degree. C. For working up, 
the organic phase was separated off, washed with cold water, dried with 
magnesium sulfate and evaporated down, after which the residue was 
distilled over a Vigreux column. 
The details of these experiments and their results are shown in Table 1. 
TABLE 1 
__________________________________________________________________________ 
Preparation of the compounds Ia 
##STR4## 
III IV Ia 
Yield Yield Yield Fragrance 
X R.sup.1 
bp. bp. bp. note 
__________________________________________________________________________ 
1 chem. 
H Single 
65% 58% 53% Fruity 
bond bond 
36.degree./0.4 mm 
Crude product 
60.degree./0.4 mm 
2 CH.sub.2 
2,3,6-CH.sub.3 
Single 
57% 46% 46% Burnt 
bond 
64.degree./0.4 mm 
60.degree./0.2 mm 
136.degree. C./0.45 mm 
Spicy 
3 CH.sub.2 
4-CH(CH.sub.3).sub.2 
Single 
77% 82% 56% Floral 
bond 
123.degree./38 mm 
Crude product 
76.degree./0.3 mm 
4 CH.sub.2 
4-CH(CH.sub.3).sub.2 
Double 
90% 43% 51% Floral 
bond 
73.degree./0.5 mm 
85.degree./0.4 mm 
142.degree./0.4 mm 
5 CH.sub.2 
3,3-CH.sub.3 
Single 
73% 55% -- -- 
bond 
60.degree./0.4 mm 
53.degree. 0.3 mm 
6 -- 2,4,4-CH.sub. 3 
Single 
-- 25% 56% Rose 
bond Crude product 
95.degree./0.15 mm 
Greenish 
__________________________________________________________________________ 
The crude products were further reacted as a solution in toluene, without 
purification. 
EXAMPLES 7 TO 14 
1 mol of cyclohexylidenealkanal (Ia) was added dropwise to a solution of 
0.63 mol of sodium borohydride in 1.2 l of ethanol at 25.degree. C. in the 
course of 2 hours. The reaction mixture was then stirred for a further 12 
hours at 25.degree. C. For working up, the reaction solution was 
evaporated down, the residue was taken up in methyl tertbutyl ether and 
10% strength H.sub.2 SO.sub.4 was added. The organic phase was separated 
off, neutralized with sodium bicarbonate solution, dried over magnesium 
sulfate and evaporated down, and the residue was distilled. 
The alcohols listed in the Table below were prepared either similarly or by 
reaction with a corresponding Grignard compound. 
TABLE 2 
__________________________________________________________________________ 
Preparation of the compounds Ib 
##STR5## 
X R.sup.1 R.sup.4 
Yield 
bp. Fragrance note 
__________________________________________________________________________ 
7 CH.sub.2 
-- H 63% 79.degree. C./0.2 mm 
Fruity, rose 
8 -- 
-- H 76% 70.degree. C./0.15 mm 
Fruity 
9 CH.sub.2 
2,3,6-CH.sub.3 
H 79% 111.degree. C./0.15 mm 
Metallic, chemical 
10 -- 
2,4,4'-CH.sub.3 
H 68% 81.degree. C./0.2 mm 
Woody, faecal 
11 -- 
2,4,4'-CH.sub.3 
CH.sub.3 
74% 94.degree. C./0.18 mm 
Aldehydic, green 
12 -- 
-- CH.sub.3 
75% 82.degree. C./0.18 mm 
Fatty, floral 
13 CH.sub.2 
4-CH(CH.sub.3).sub.2 
H 76% 100.degree. C./0.3 mm 
Fruity, floral 
14 CH.sub.2 
4-CH(CH.sub.3).sub.2 
CH.sub.3 
67% 120.degree. C./0.3 mm 
Woody, spicy 
__________________________________________________________________________ 
EXAMPLES 15 TO 19 
60 mmol of cyclohexylidenealkanol (Ib) were added dropwise to 7.5 ml of 
boron trifluoride etherate in 45 ml of methylene chloride at 0.degree. C. 
The reaction solution was stirred for 2 hours, poured onto ice water and 
then extracted with methylene chloride. Working up in the conventional 
manner gave the spirocyclic ethers Ic. 
The details of these experiments and their results are shown in Table 3. 
TABLE 3 
__________________________________________________________________________ 
Preparation of the compounds Ic 
##STR6## 
Fragrance note 
X R.sup.1 R.sup.4 Yield 
bp. 
100% 10%.sup.1 
__________________________________________________________________________ 
15 CH.sub.2 
-- H 75% -- 
16 CH.sub.2 
7,7-CH.sub.3 
H 80% Faecal, Leather-like 
leather-like 
17 CH.sub.2 
7,7-CH.sub.3 
CH.sub.3 
80% Faecal, Herbaceous 
herbaceous 
18 CH.sub.2 
7,7-CH.sub.3 
CHCH.sub.2 
78% Faecal, sage 
Sage 
19 CH.sub.2 
8-CH(CH.sub.3).sub.2 
H 75% Civet Civet 
__________________________________________________________________________ 
.sup.1 10% strength solution in ethyl alcohol