Patent CA-1053688-A (CA)
Title: Enol esters and novel flavoring and fragrance compositions containing same and processes for using same and processes for preparing said novel enol esters
Inventor: PITTET ALAN O
IPC: A23L27/00
Filed: 1976-03-10
Granted: 1979-05-01
Abstract: Abstract:  Processes and compositions are described for the use in foodstuff, chewing gum, toothpaste and medicinal product flavor and aroma, tobacco flavor and aroma and perfume aroma augmenting, modifying, enhancing and imparting compositions and as foodstuff, chewing gum, toothpaste, medicinal product, tobacco, perfume and perfumed article aroma imparting materials of one or more alkyl side chain methyl substituted or unsub-stituted 2,2,6-trimethyl-1-cyclohexen-1-vinyl alkanoates (hereinafter referred to as "enol esters") having the generic structure:                             (which structure is intended to cover both the "cis" and the "trans" isomers thereof) wherein R1 is C1-C11 alkyl and R4 is hydrogen or methyl, produced by one of the following processes:       (1)  A process which comprises the step of oxidizing beta-ionone or a beta-ionone homologue having the formula:     with a peracid having the formula:                             wherein R1 is C1-C11 alkyl; R4 is hydrogen or methyl; and R2 is hydrogen, methyl, ethyl or metachlorophenyl and in the presence of a buffer and a solvent which is one of: methylene chloride; acetic acid; formic acid; propionic acid; benzene; cyclohexane; formamide; chloroform; or mixtures of two or more of the foregoing solvents and in the absence of substantial quantities of reactive solvents such as dimethyl aniline or, where a buffer is not present, dimethyl formamide, to form alkyl side chain substituted or unsubstituted 2,2,6-trimethyl-1-cyclohexen-1-vinyl alkanoates (hereinafter referred to as "enol esters") having the formula:                       (which would be primarily the "trans" isomer when produced in this manner);    (2)  If desired reacting an enol acetate formed by the process (1) when R1 is CH3 and R4 is hydrogen) having the structure:             or         with an alkanoic acid anhydride or an acyl halide having one of the formulae:                or           wherein X is bromo or chloro, and wherein R3 is C2-C11 alkyl such as ethyl, n-propyl, isopropyl, 1-butyl, 2-butyl, 2-methyl-1-propyl, 2-methyl-2-propyl, n-heptyl, 2-methyl-1-nonyl, n-octyl and n-undecyl, in the presence of a catalyst such as paratoluene sulfonic acid or an alkali metal acetate to form a compound having the formula:         (a mixture of "cis" and "trans" isomers); or (3)  Reacting beta-cyclohomocitral having the formula:                 with a lower alkanoic acid anhydride having the formula:                 of an acyl halide having the formula:                 wherein X is bromo or chloro and wherein R1 is C1-C11 alkyl, in the presence of an alkali metal acetate under reflux conditions or in the presence of paratoluene sulfonic acid under reflux conditions to form a mixture of "cis" and "trans" isomers.    Addition of one or more of the enol esters having the formula:                             to consumable materials is indicated to produce:    (a)  In foodstuffs, foodstuff flavorings, chewing gums, toothpastes and medicinal products, "damascenone-like" (damascenone has the structure:                            , sweet, "cocoa like", "dried fruit-like", fruity, apple juice-like, sweet carrot juice, incense-like, ionone-like, spicey, woody, wood resin-like, winey, oriental/olibanum, clove-like, camphoraceous, rosey, raspberry, raspberry seed, grape, violet-like, caryophyllene-like, and/or floral aromas with fermented tea and tobacco nuances and sweet vegetable, tea, sweet carrot juice, sweet, fruity, dried fruit-like, apple juice, mimosa, raspberry, pear, ionone-like, "damascenone-like", rosey, woody, camphor-aceous, violet, cedarwood-like, caryophyllene-like, wood resin-like, winey, tobacco-like, hay-like, and raspberry kernel tastes (with sweet aftertastes);  (b)  In tobacco and tobacco flavorings, a sweet, floral, fruity, woody, ionone-like, spicey slightly fatty aromatic aroma prior to smoking and a sweet, tobacco-like characteristic in the mainstream on smoking; and (c)  In perfumes, colognes and perfumed articles, sweet, fruity, acidic-fruity, dried fruit-like, floral, "damascenone-like", woody, green, beta-ionone-like notes with animal-tobacco nuances and fermented tea and tobacco topnotes and cognac, balsamic, tobacco undertones.  The enol esters of our invention are also useful reaction intermediates for producing beta-cyclohomocitral which is valuable for its organoleptic properties.  There has been considerable work performed relating to substances which can be used to impart (modify, augment or enhance) flavors and fragrances to (or in) various consumable materials.  These substances are used to diminish the use of natural materials, some of which may be in short supply and to provide more uniform properties in the finished product.  "Damascenone-like" (damascenone has the structure:                             sweet, "cocoa like", "dried fruit-like", fruity, apple juice-like, sweet carrot juice, incense-like, ionone-like, spicey, woody, wood resin-like, winey, oriental/olibanum, clove-like, camphoraceous, rosey, raspberry, raspberry seed, grape, violet-like caryophyllene-like, and/or floral aromas with fermented tea and tobacco nuances and sweet vegetable, tea, sweet carrot juice, sweet, fruity, dried fruit-like, apple juice, mimosa, raspberry, pear, ionone-like, "damascenone-like", rosey, woody, camphoraceous, violet, cedarwood-like, caryophyllene-like, wood resin-like, winey, tobacco-like, hay-like, and raspberry kernel tastes (with sweet aftertastes) are particularly desirable for many uses in foodstuff flavors, chewing gum flavors, toothpaste flavors and medicinal product flavors.       Sweet, fruity, acidic-fruity, dried fruit-like, woody, green beta-ionone-like notes with animal-tobacco topnotes and cognac, balsamic, tobacco undertones are desirable in several types of perfume compositions, perfumed articles and colognes.       Sweet, woody, floral, fruity, ionone-like, spicey, slightly fatty aromatic aromas prior to smoking and sweet, tobacco-like smoke aroma characteristics in the mainstream on smoking are desirable in tobaccos and in tobacco flavor-ing compositions.       Arctander, "Perfume and Flavor Chemicals", 1969 discloses the use in perfume compositions and flavors of "cyclocitral", "dehydro-beta-cyclocitral", "isocyclocitral", "alpha-cyclo-citrylidene acetaldehyde" and "beta-cyclocitrylidene acetal-dehyde", thus:     (i)  "760" CYCLOCITRAL      Alpha-cyclocitral = (2,2,6-trimethyl-5-cyclohexen-1-carboxaldehyde). beta-cyclocitral = (2,2,6-trimethyl-6-cyclohexen-1-carboxaldehyde). Both isomers are known and have been produced separately.                                Very rarely offered commercially. These particular cyclocitrals have little or no interest to the creative perfumer, but they have served as part of may pieces of proof that isomers (alpha-beta) do often have different odors."         (ii) "761? iso-CYCLOCITRAL      A mixture of two chemicals: 3,5,6-trimethyl-3-cyclohexen-1-carboxaldehyde (meta-cyclocitral).                                      (corrected structure) 2,4,6-trimethyl-4-cyclohexen-1-carboxaldehyde (symmetric-iso-cylocitral).                            (corrected structure) Powerful, and diffusive, foliage-green, "dark" weedy and dry odor, sometimes described as "Flower-shop odor".  The earthy and wet green notes are quite natural in high dilution and resemble the odor of stems from plants and flowers fresh from the soil.    Finds use in perfume compositions whereit blends excellently with Oakmoss products (compensates for sweetness and lifts the topnote), with Ionones (freshness), Geranium and Galbanum (enhances the green and "vegetable" notes), etc..."     (iii)   "762:  alpha CYCLOCITRYLIDENE ACETALDEHYDE                             Mild, floral-woody, somewhat oily-herbaceous odor, remotely reminiscent of Rose with similarity  to the odor of hydrogenated Ionones.       Suggested for use in perfume compositions. It brings a certain amount of floral lift to Rose compositions, and performs fairly well even in soap.  However, the cost of the rarely offered and never readily avail-able lots are rather discouraging to the perfumer, and it is most conceivable that, this material can be left out of the perfumer's library without any great loss.  ..."         (iv)    "763: beta-CYCLOCITRYLIDENE ACETALDEHYDE         2,6,6-trimethyl-1-cyclohexenyl-beta-acrolein.                             Sweet-woody, rather heavy odor, resembling that of beta-Ionone.  More fruity than really floral, but not as tenacious as the Ionone.       Suggested for use in perfume compositions, but since it does not offer any new or unusual odor characteristics, and it cannot be pro-duced in economical competition to beta-Ionone, there is little or no chance that it will ever become a standard shelf ingredient for the perfumer.  ..."         (v)     "869:  DEHYDRO-beta-CYCLOCITRAL (Safranal) 2,6,6-trimethyl-4,4-cyclohexadiene-1-carboxaldehyde   Very powerful, sweet, green-floral and some-what tobacco-herbaceous odor of good tenaci-ty. In extreme dilution reminiscent of the odor of Safran (Saffron).     beta Interesting material for fresh topnotes, as a modifier for aldehyde-citrusy notes, as a green-floral topnote in flower fragrances, etc.  It blends excellently with the ali-phatic Aldehydes, with Oakmoss products and herbaceous oils.  ..."       Safranal and beta-cyclocitral are disclosed as volatile constituents of Greek Tobacco by Kimland et al., Phytochemistry 11 (309) 1972.  Beta-cyclocitral is disclosed as a component of Burley Tobacco flavor by Demole and Berthet, Helv. Chim. Acta.  55 Fasc 6, 1866 (1972).      Methods for producing enol esters are disclosed in the prior art.  Thus, for example, heptaldehyde enol acetate is disclosed to be produced according to the process of reacting heptaldehyde with acetic anhydride in the presence of crystalline potassium acetate at reflux temperatures of 155-160°C by Bedoukian, J. Am, Chem. Soc. 66, August, 1944, pages 1325-1327.         However, no disclosures exist in the prior art indicating the existence or implying the organoleptic uses of enol esters related to those of the instant invention or methods for synthesizing such compounds.