Abstract:
A fixative for perfume compositions, 1-(2,6,6-trimethylcyclohexyl)-hexane-3-ol, itself odorless to many people, brings about a &#34;rounding-off&#34; of the perfume while increasing its intensity. The compound is made by condensation of citral with pentane-2-on, followed by cyclization and hydration.

Description:
FIELD OF INVENTION 
     The present invention relates to the new compound 1-(2,6,6-trimethyl-cyclohexyl)-hexane-3-ol having the structural formula I, ##STR1## its manufacture, as well as its use as fixative for perfume compositions. 
     SUMMARY OF INVENTION 
     It has been found that an addition of 1-(2,6,6,-trimethyl-cyclohexyl)-hexane-3-ol effectively brings about a &#34;rounding-off&#34; and fixation of perfume compositions while simultaneously increasing the intensity of the fragrance. The quantity used amounts usually to 1 to 25% by weight relative to the total composition, and a very distinct fixing effect can be ascertained particularly from approximately 3%. In principle, more than 25% may also be employed; this depends, however, upon the nature of the total composition and may be easily determined by routine experiments. The term &#34;perfume composition&#34; is meant to here define a so-called perfume oil, in other words, the concentrate, which is then thinned to obtain a perfume, or which is used for scenting cosmetic products, for example, soaps, hair lotions or creams. Such a perfume oil contains, in addition to the fixative, odoriferous substances and volatile oils. 
     DETAILED DESCRIPTION OF EMBODIMENTS 
     The 1-(2,6,6-trimethylcyclohexyl)-hexane-3-ol itself is not to be considered as an odoriferous substance in the conventional sense as this saturated secondary alcohol has been found to be odorless, or only very slightly scented, by a significant number of the test persons who were asked to judge this substance, whereas other persons perceived an intensely radiating wood-like, slightly animalic-urinary odor. 
     Anosmia, i.e. the incapability to perceive smells, which numerous people have with respect to this new alcohol, may be compared with the effect of various very expensive animalic fixatives, such as musk and amber, whose scent can also be noticed only faintly by certain people, or not at all. 
     The occurrence of anosmia with respect to a specific substance, particularly in the area of perfumery, appears to always point out to particularly good fixative properties of a substance and holds true at least for all of the fixatives which have heretofore been employed in the manufacture of perfume compositions. These afore-mentioned advantageous properties of 1-(2,6,6-trimethylcyclohexyl)-hexane-3-ol distinguish this substance from the homologous products which have been known for a long time, such as iso-tetrahydromethylionol and n-tetrahydromethylionol, which do not develop any fixative effect and with regard to which also no cases of anosmia have been ascertained. 
     The product 1-(2,6,6-trimethylcyclohexyl)-hexane-3-ol may be obtained, analogous to the method disclosed in the Journal of the American Chemical Society 46, 119 (1924) and Helv. Chim. Acta 26, 2151 (1943), by condensation of citral with pentane-2-on in the presence of bases to 8,12-dimethyltrideca-5,7,11-tri-en-4-on, cyclization thereof with phosphoric acid, and subsequent total hydration of the cyclization product. For example, the condensation may be carried out in the presence of alkali hydroxide, such as NaOH or KOH, e.g. in an alcoholic solution, at about room temperature, in an inert solvent. The cyclization may be carried out by a slow addition of phosphoric acid at slightly below room temperature, a subsequent slight heating to room temperature while stirring for several hours, and renewed slight heating to approximately 10° C. above room temperature again while stirring for several hours. The hydration may suitably be carried out catalytically under pressure using, e.g. Raney nickel, and at a temperature rising to 150°-200° C. 
     The following examples show, on the one hand, the manufacture of the new compound 1-(2,6,6-trimethylcyclohexyl)-hexane-3-ol and, on the other hand, some formulations for the use of 1-(2,6,6-trimethylcyclohexyl)-hexane-3-ol as fixative in perfume oils. 
    
    
     EXAMPLE 1 
     Manufacture of 1(2,2,6-trimethylcyclohexyl)-hexane-3-ol 
     First Stage: 
     Dropped into 1,520 grams of citral and 1,720 grams of methyl-n-propyl ketone while stirring at a temperature of 20°-25° C., are 32 grams of sodium hydroxide dissolved in 200 ml methanol. The reaction medium is stirred at that temperature for 24 hours. Thereafter, neutralization is effected with 60 grams glacial acetic acid, the reaction water formed is separated, and the solvent as well as any excess of methyl-n-propyl ketone are distilled off. The reaction product is purified by distillation. The yield is 1.66 kilograms of 8,12-dimethyltrideca-5,7,12-tri-en-4-on. 
     Kp 2  (boiling point): 225° C., d 4   20  =0.9134; n D   20  =1.5232. 
     Second Stage: 
     1.66 kilograms of 8,12-dimethyltrideca-5,7,12-tri-en-4-on dissolved in 3 kilograms benzene are dropped while stirring at 10°-15° C. into 1.66 kilograms phosphoric acid and the reaction mixture is stirred for 2 hours at 20° C. and thereafter for 3 hours at 30° C. Thereupon water is added, the aqueous phase is extracted twice with benzene, the benzene extract is neutrally washed with sodium carbonate solution, and the benzene is then removed by distillation. The reaction product is purified by distillation. The yield is 1.3 kilograms 1-(2&#39;,6&#39;,6&#39;-trimethylcyclohex-2&#39;-enyl)-hex-1-en-3-on. 
     Kp 2  : 190° C., d 4   20  =0.9389; n D   20  =1.4953. 
     Third Stage: 
     1.3 kilograms of 1-(2&#39;,6&#39;,6&#39;-trimethylcyclohex-2&#39;-enyl)-hex-1-en-3-on are hydrated in the presence of Raney nickel as catalyst at 100 atmospheres excess H 2  pressure, until 3 mol H 2  have been absorbed. In the course of the hydration, the reaction temperature is increased to 180° C. The hydration product is purified by distillation. The yield is 1.1 kilogram 1-(2&#39;,6&#39;,6&#39;-trimethylcyclohexyl)-hexane-3-ol. 
     Kp 2  : 123° C.; d 4   20  =0.9147; n D   20  =1.4720. 
     EXAMPLE 2 
     Rose Bouquet 
     
         ______________________________________300 grams  phenyl ethyl alcohol200 grams  citronellol100 grams  geraniol100 grams  phenyl ethyl acetate50 grams   aldehyde C 11 undecylene, 10% in DPG50 grams   geranium oil Bourbon50 grams   trichloro phenyl ethyl acetate40 grams   ionone beta30 grams   citronellyl acetate20 grams   aldehyde C 9, 10% in DPG20 grams   iron beta, 10% in DPG      4-methyl-2-isobutenyl tetrahydro pyrane in a10 grams   10% DPG solution970 grams______________________________________ 
    
     When 30 grams 1-(2,6,6-trimethylcyclohexyl)-hexane-3-ol are added to the above mixture, it provides to the mixture a radiating fragrance which is noticeable for a considerably longer period of time than the fragrance or aroma of the above mixture without such addition. 
     EXAMPLE 3 
     Perfume Oil with an Exotic, Flowery Aroma 
     
         ______________________________________140 grams    phenyl ethyl alcohol120 grams    alpha-hexyl-cinnamic aldehyde100 grams    benzylacetate90 grams hydroxy-citronellal85 grams p-tert. butyl-α-methyl dihydrocinnamic aldehyde85 grams French lavender oil 4=/42%65 grams nerol40 grams cumarin40 grams musk ketone40 grams musk ambrette25 grams linalool20 grams amyl salicylate20 grams eugenol20 grams ylang-ylang oil extra15 grams patchouli oil Singapore10 grams vanillin5 grams  iron beta920 grams______________________________________ 
    
     An addition of 100 grams 1-(2,6,6-trimethylcyclohexyl)-hexane-3-ol intensifies the flowery aroma and imparts to the perfume a considerably longer adherence. 
     EXAMPLE 4 
     Perfume Oil with a Wood-Like-Powdery Aroma for Soaps 
     
         ______________________________________150 grams      benzyl benzoate100 grams      cumarin100 grams      geraniol100 grams      lavandin abrialis100 grams      linalyl acetate75 grams       phenyl ethyl alcohol65 grams       patchouli oil Sing. rect.50 grams       linalool35 grams       geranium oil Bourbon20 grams       alpha-hexyl-cinnamic aldehyde20 grams       East Indian sandalwood oil5 grams        anisealdehyde2 grams        aldehyde C 12 laurin822 grams______________________________________ 
    
     An addition of 228 grams 1-(2,6,6-trimethylcyclohexyl)-hexane-3-ol imparts to the previously somewhat dull and flat-smelling perfume composition a long-lasting, radiant and natural fragrance. 
     It will be obvious to those skilled in the art that various changes may be made without departing from the scope of the invention and the invention is not to be considered limited to what is described in the specification.