The instant invention provides methyl substituted-2-oxohexane derivatives and processes for preparing same as well as processes for using same for augmenting or enhancing the aroma of perfume compositions, colognes and perfumed articles. The methyl substituted-2-oxohexane derivatives of our invention are defined according to the structure: ##STR3## wherein R.sub.12 represents hydroxyl having the structure: EQU --OH]
or acetoxy having the structure: ##STR4## and wherein R.sub.3, R.sub.4, R.sub.5, R.sub.6 and R.sub.7 each represent the same or different methyl or hydrogen with the provisos that:
(i) the sum total of the carbon atoms of R.sub.3, R.sub.4, R.sub.5, R.sub.6 and R.sub.7 is three; PA1 (ii) when R.sub.7 is methyl, then R.sub.5 and R.sub.6 are each methyl; and PA1 (iii) when R.sub.7 is hydrogen, then R.sub.3 or R.sub.4 is methyl. PA1 (i)--Murphy & Lane, Ind. Eng. Chem., Prod. Res. Dev., Vol. 14, No. 3, 1973, p. 167 (Title: Oligomerization of 2-Methyl-2-Butene in Sulfuric Acid and Sulfuric-Phosphoric Acid Mixtures). PA1 (ii)--Whitmore & Mosher, Vol. 68, J. Am. Chem. Soc., February, 1946, p. 281 (Title: The Depolymerization of 3,4,5,5-Tetramethyl-2-Hexene and 3,5,5-Trimethyl-2-Heptene in Relation to the Dimerization of Isoamylenes). PA1 (iii)--Whitmore & Stahly, Vol. 67, J. Am. Chem. Soc., December, 1945, p. 2158 (Title: The Polymerization of Olefins. VIII The Depolymerization of Olefins in Relation to Intramolecular Rearrangements. II). PA1 (iv)--U.S. Pat. No. 3,627,700, issued on Dec. 14, 1971, (Zuech). PA1 (v)--U.S. Pat. No. 3,538,181, issued on Nov. 3, 1970, (Banks). PA1 (vi)--U.S. Pat. No. 3,461,184 issued on Aug. 12, 1969 (Hay, et al). PA1 (vii)--Tausz, Chemische Zentralblatt, 1919, II, 125, (Production of Di-isoamylene From Isoamylene Using Mercury Acetate Catalyst).
Chemical compounds which can provide woody, camphoraceous, patchouli-like, fruity and amber-like aromas are highly desirable in the art of perfumery. Many of the natural materials which provide such fragrances and contribute such desired nuances to perfumery compositions and perfumed articles are high in cost, unobtainable at times, vary in quality from one batch to another and/or are generally subject to the usual variations in natural products.
There is, accordingly, a continuing effort to find synthetic materials which will replace, enhance or augment the fragrance notes provided by natural essential oils or compositions thereof. Unfortunately, many of the synthetic materials either have the desired nuances only to a relatively small degree or they contribute undesirable or unwanted odor to the compositions.
Application for U.S. Letters Patent Ser. No. 184,132 filed on Sept. 4, 1980 now U.S. Pat. No. 4,321,255 issued on Mar. 23, 1982 (incorporated by reference herein) discloses the production of unsaturated branched ketones according to the reaction: ##STR5## wherein in each of the structures containing dashed lines, these structures represent mixtures of molecules wherein in each of the molecules, one of the dashed lines represents a carbon-carbon double bond and each of the other of the dashed lines represent a carbon-carbon single bond. These compounds so produced are indicated to be useful for their organoleptic properties in augmenting or enhancing the aroma or taste of consumable articles including perfume compositions and colognes. It is noteworthy that the compounds defined according to the structure: ##STR6## have unsaturation in the structure and, in addition, contain twelve carbon atoms rather than ten carbon atoms. Disclosure of the resulting alcohols produced by reaction of these ketones with methyl magnesium halide is set forth in application for U.S. Letters Patent Ser. No. 212,887 filed on Dec. 4, 1980 (now U.S. Pat. No. 4,318,934 issued on Mar. 9, 1982). The resulting alcohols have thirteen carbon atoms rather than the ten carbon atom containing alcohols of the instant application.
Nothing in the prior art discloses compounds defined according to the generic structure: ##STR7## wherein R.sub.1, R.sub.2, R.sub.3, R.sub.4, R.sub.5, R.sub.6 and R.sub.7 are defined supra.
"Diisoamylene" is indicated to be synthesized in the following references:
United Kingdom Pat. No. 796,130 published on June 4, 1958 discloses the synthesis of polyalkylindanes by means of, interalia, reacting alpha-methylstyrene with trimethylethene (2-methyl-butene-2) in the presence of an acid catalyst such as sulfuric acid or boron trifluoride methyletherate. It is further indicated that such compounds are useful intermediates in the production of perfumery compounds. Apparently, however, the more volatile diisoamylenes produced as side-products in the reaction of 2-methyl-butene-2 with alpha-methylstyrene are discarded.
The diisoamylene useful as a starting material in the instant case may be distilled from the reaction product (as see Example A infra) at a temperature in the range of 36.degree.-40.degree. C.; a liquid temperature in the range of 74.degree.-94.degree. C. and a pressure of 4-5 mm/Hg.