Process for augmenting or enhancing the aroma or taste of raspberry flavored foodstuffs using 2,6,6-trimethylcyclohexene derivatives

Described is a process for augmenting or enhancing the aroma or taste of raspberry flavored foodstuffs comprising the step of adding to a foodstuff, an aroma augmenting or enhancing quantity of certain 2,6,6-trimethylcyclohexene derivatives.

BACKGROUND OF THE INVENTION 
The present invention provides butenoyl and butanoyl cyclohexane and 
cyclohexene compounds defined by the generic structure: 
##STR1## 
wherein in the cyclohexyl group one of the dashed lines is a double bond 
and the other two dashed lines are single bonds or each of the three 
dashed lines are single bonds; in the butanoyl side chain, the dashed line 
is a single bond or a double bond and wherein one of R.sub.1 or R.sub.2 is 
methyl and the other of R.sub.1 or R.sub.2 is hydrogen. These compounds 
are prepared by a straightforward economical process also covered by this 
invention, which process involves the treatment with hydrogen of a 
compound having the generic structure: 
##STR2## 
wherein one of the dashed lines or both of the dashed lines are 
carbon-carbon double bonds and wherein one of R.sub.1 or R.sub.2 is 
hydrogen and the other of R.sub.1 or R.sub.2 is methyl. The compounds are 
prepared by means of the following reaction sequence: 
##STR3## 
wherein the cyclohexyl moiety of structure (II) contains a maximum of two 
double bonds only when the cyclohexyl moiety of structure (I) contains two 
double bonds. 
The present invention also provides for the utilization of the compounds 
produced by our invention and mixtures produced by the process of our 
invention which contain the compounds having the chemical structures: 
##STR4## 
or defined by the generic structure: 
##STR5## 
wherein R.sub.1, R.sub.2 and the dashed lines are as above defined, for 
their organoleptic properties in perfumes, perfumed articles, foodstuffs, 
foodstuff flavoring compositions, chewing gums, toothpastes, medicinal 
products, tobaccos, tobacco flavoring compositions, substitute tobaccos 
and substitute tobacco flavoring compositions. 
In the perfumery art there is considerable need for constituents having 
floral, rose-like, sweet, dry fruity, tobacco-like aromas with heavy 
fruity (berry), hay-like and slightly camphoraceous undertones. Sweet, 
full ripe raspberry-like, fruity, grape juice-like, apple juice-like, 
dried-fruit-like damascenone-like, floral, woody, aroma and flavor 
characteristics are desirable in many fruit flavors, particularly 
raspberry flavors, tangerine flavors, grape flavors and apple flavors. 
Wheat, fruity hay-like, minty/spicey and woody aromas both prior to and on 
smoking in the mainstream and in the sidestream are desirable in smoking 
tobacco flavoring compositions and substitute smoking tobacco flavoring 
compositions. 
Specifically described herein are materials having such an organoleptic 
profile but which do not discolor with age. Such materials have a wide 
utilization in the presence of perfume compounds and in foodstuff flavor 
and tobacco flavoring compounds. A limited amount of such materials that 
give rise to one or more of these properties individually, is available 
from natural sources but the natural materials are subject to wide 
variations in quality, are expensive and are often in critically short 
supply. 
In addition, there is a continuing search for flavor compositions which can 
vary, fortify, modify, enhance, augment or otherwise improve the flavor 
and/or aroma of foodstuffs, medicinal products, toothpastes and chewing 
gums. To be satisfactory, such compositions should be stable, non-toxic 
and blendable with other ingredients to provide their own unique flavor 
and aroma nuances without detracting from the contributions of the 
co-ingredients. Preferably such compositions should be naturally occurring 
or present in natural foodstuffs so that their ingestible safety can be 
readily recognized. These materials should be capable of being synthesized 
in a simple and economical manner. The need for safe flavors in the berry 
fruit flavor area, especially the raspberry area, the grape flavor area 
and the apple flavor area is well known particularly in the fruit juice, 
ice cream and yogurt flavor areas. More specifically, there is a need for 
the development of non-toxic materials which can replace natural materials 
not readily available having sweet, full ripe, raspberry--like, fruity, 
grape juice-like, apple juice-like, dried-fruit-like, floral and woody 
aroma and flavor characteristics. 
The instant invention provides the foregoing which the prior art has 
heretofore failed to provide. Furthermore, nothing in the prior art shows 
the unexpected, unobvious and advantageous value of carrying out a 
hydrogenation process on compounds having the generic structure: 
##STR6## 
wherein at least one of the dashed lines of structure (I) is a 
carbon-carbon double bond and the other of the dashed lines is a 
carbon-carbon single bond and one of R.sub.1 or R.sub.2 is hydrogen and 
the other of R.sub.1 or R.sub.2 is methyl, to provide compounds having the 
generic structure: 
##STR7## 
wherein at least two of the dashed lines in the cyclohexane moiety of 
structure II is a carbon-carbon single bond and the other of the dashed 
lines in the cyclohexane moiety of structure II is either a carbon-carbon 
single bond or a carbon-carbon bond; and wherein the dashed line in a 
butanoyl moiety of structure II is a carbon-carbon single bond or a 
carbon-carbon double bond and one of the moieties R.sub.1 or R.sub.2 is 
hydrogen and the other of the moieties R.sub.1 or R.sub.2 is methyl. 
Described in a prior art are mixtures presumed to be predominantly cis, 
trans-delta-damascone with minor amounts of trans, trans-delta-damascone 
(Ayyar, Cookson and Kagi, J. Chem. Soc., Perkin Trans. 1, 1975 (17) 
1727-36 [title: "Synthesis of Delta-Damascone 
[trans-1-(2,6,6-trimethylcyclohex-3-enyl)but-2-en-1-one] and 
Beta-Damascenone 
[trans-1-(2,6,6-trimethylcyclohexa-1,3-dienyl)but-2-en-1-one]"]. The 
reaction sequence of the Ayyar synthesis, however, does not concern the 
step of hydrogenation and is as follows: 
##STR8## 
wherein the wavy line is representative of a "cis" or "trans" 
configuration of the methyl moiety with respect to the acetyl or crotonoyl 
moiety, both of which are bonded to the cyclohexenyl moiety, the "cis" 
isomer presumably being the major isomer and the "trans" isomer presumably 
being the minor isomer in this reaction sequence. 
In U.S. Pat. No. 3,956,392 at column 7 and 8 it is indicated that 
trans,e-1-crotonyl-2,2,6-trimethylcyclohexane (totally saturated insofar 
as the ring moiety is concerned) has unexpected, unobvious properties over 
cis,e-1-crotonyl-2,2,6-trimethylcyclohexane; e-beta-damascenone and 
e-beta-damascone. The properties of the compound of U.S. Pat. No. 
3,956,392 are different in kind rather than degree from the organoleptic 
properties of the mixtures produced according to the hydrogenation 
processes of our invention. 
Swiss Pat. No. 537,352 issued on July 13, 1973 discloses 
1(2-butenoyl)cyclohexenes having the structure: 
##STR9## 
(wherein R may be hydrogen) and this Swiss Patent is abstracted in Chem. 
Abstracts 79:104808s. 
The article, "Structure et synthese de la damascenone 
(trimethyl-2,6,6-trans-crotonoyl-1-cyclohexadiene-1,3), constituant 
odorant de 1'essence de rose bulgare (Rosa damascena Mill.)" by E. Demole, 
P. Enggist, U. Sauberli and M. Stoll (referred to herein as Demole, et. 
al.) discloses the presence of 
2,6,6-trimethyl-1(trans-crotonyl)-1,3-cyclohexadiene as an "odorous 
constituent of Bulgarian rose oil". In addition, the Demole et. al. 
article discloses that dihydro-alpha-damascone results from the "catalytic 
hydrogenation" of "dehydro-alpha-damascone" produced via 
"dehydro-iso-ionol". On page 550 of the Demole article, 
1,5,5(trimethylbutyne-2-oyl)-6-cyclohexene is indicated to be treated with 
a Lindlar catalyst of the type used in the instant case thereby producing 
a mixture containing 4:1 (mole ratio) of alpha-cis-damascone and 
dihydro-alpha-damascone. The use of such Lindlar catalyst as is set forth 
in the Demole et. al. reference is well known in the art as is seen in 
Canadian Patent 1,022,187 wherein citral, 3,7-dimethyl-2,6-octadienal is 
converted to citronellal with yields in excess of 95% by the use of a 
palladium catalyst and hydrogen gas in an alkaline alcoholic reaction 
medium. It is indicated that the palladium can be used in any form in 
Canadian Patent No. 1,022,187 but prefereably that the palladium is 
supported on a "suitable inert carrier such as charcoal, alumina, barium 
carbonate, aluminum sulfate, carbon or silica gel". 
Nothing in Canadian Patent No. 1,022,187 or in the Demole et. al. article 
implied that the catalyst of the instant case can be used in such a manner 
in conjunction with the hydrogenation of compounds having the generic 
structure: 
##STR10## 
wherein the dashed lines and R.sub.1 and R.sub.2 are as defined above, 
whereby compounds having the generic structure: 
##STR11## 
in admixture in the proportions indicated can be produced. 
In addition, none of the foregoing references discloses the treatment with 
hydrogen of any one of the genus of compounds having the structure: 
##STR12## 
wherein at least one of the dashed lines is a carbon-carbon double bond 
and the other of the dashed lines is a carbon-carbon single bond and 
wherein one of R.sub.1 or R.sub.2 is hydrogen and the other of R.sub.1 or 
R.sub.2 is methyl.