EP0018833B1

EP0018833B1 - Compounded perfumery composition

Info

Publication number: EP0018833B1
Application number: EP80301436A
Authority: EP
Inventors: Gerald John Ferber; Jacqueline Ann Botten; Michael Mellor
Original assignee: Bush Boake Allen Ltd
Current assignee: Bush Boake Allen Ltd
Priority date: 1979-05-04
Filing date: 1980-05-01
Publication date: 1983-10-19
Also published as: EP0018833A3; DE3065352D1; JPS55149207A; GB2049422A; AU5803380A; ATE5083T1; EP0018833A2

Abstract

The dihydropyran and dioxan which may be obtained by the Prins reaction between allo-ocimene and formaldehyde have been discovered to possess attractive floral odours. They are useful as ingredients of compounded perfumery compositions. There novel triene alcohols are also produced by the Prins reaction which find use as intermediates in the preparation of the dihydropyrans and dioxans. The cis isomer of the dihydropyran may be converted into the trans isomer. The dihydropyran wherein at least 10% of the compound takes the form of the trans isomer is novel.

Description

The perfumery compositions to which this invention relates are those of the type where a number of odiferous materials of synthetic or natural origin are admixed or compounded to form a perfumery concentrate. Such concentrates may find use as such or after dilution but more usually they are added in small proportions to other materials such as to space sprays or to soap, detergent, cosmetic or deodorant compositions or to substrates such as fabric, fibre, or paper products in order to provide them with agreeable olfactory properties. Thus such concentrates are products of commerce and may comprise a simple or complex mixture of perfumery compounds.
The perfumery industry devotes a great deal of effort to the evaluation of the odiferous properties of a variety of chemical compounds which may be obtained from synthetic or natural sources. One group of chemicals which are the subject of particular interest is composed of the synthetic derivatives of terpenic hydrocarbbns. Of the many such derivatives which have been synthesised only a small proportion have proved to have sufficiently attractive odiferous properties to become widely used as ingredients of compounded perfumery compositions.
We have now discovered that a group of products which may be prepared from the triene allo-ocimene (2,6 dimethyl-octa-3,5,7-triene) which are useful as ingredients of compounded perfumery compositions.
This group of products may be obtained by means of a Prins reaction between allo-ocimene and formaldehyde.
The Prins reaction between allo-ocimene and para-formaldehyde in dichloromethane under reflux in the presence of acetic acid has been reported in Nippon Kagaku Kaishi 1977 (8) p. 1253-5. The product of this reaction is reported to comprise a mixture of a dihydropyran having the formula:
and the cis and trans isomers of a dioxan having the formula:-
The synthesis of a number of pyrans and dioxanes has been reported in the literature together with, in some instances, an evaluation of the odiferous properties of these compounds. West German Patent 1467512, Swiss Patent 604560 (see especially column 3, line 1 thereof), Swiss Patent 414674 and French Patent 1310750 (see especially the left hand column on page 2, lines 33 to 40) all describe pyrans, and in some instances, the odiferous properties thereof. Belgian Patent 673628 and United States Patent 3423430 both describe the synthesis of dioxanes and the odiferous properties of some of these. We have now discovered that the products which may be obtained by the Prins reaction of allo-ocimene with formaldehyde possess attractive floral odours. Thus our invention provides a compounded perfumery composition which comprises a plurality of known odoriferous ingredients together with at least one compound having the formula 1:-
wherein X may represent an oxygen atom in which case R_i represents a 4-methyl penta-1,3-dien-1-yl group and R₂ represents a hydrogen atom or X may represent a methinyl group which is doubly bonded to C, and singly bonded to C₂ in which case R_i disappears and R₂ represents a 2-methyl-prop-1-en-1-yl group.
The compound wherein X represents a methinyl group i.e. the dihydropyran and the compound wherein X represents an oxygen atom i.e. the dioxan both exist in two stereoisomeric forms i.e. cis and trans geometrical isomers. Mixtures of these isomers or the individual stereoisomers are useful according to our invention.
The dihydropyran has been discovered to possess an attractive floral odour. The dioxan has been discovered to possess a floral odour having a degree of citrus character.
The novel perfumery compositions may be compounded according to recognised techniques or perfumery employing known odiferous perfumery ingredients, e.g. techniques and ingredients mentioned in the standard textbooks "Soap, Perfumery and Cosmetics" by W. A. Poucher, 7th edition published by Chapman & Hall (London) 1959; "Perfume and Flavour Chemicals" by S. Arctander, published by the author (Montclair) 1959 and "Perfume and Flavour Materials of Natural Origin" also by S. Arctander, self-published, Elizabeth NJ, 1960.
Typical perfumery materials which may form part of compounded composition include: natural esential oils such as lemon oil, mandarin oil, clove leaf oil, petitgrain oil, cedar wood oil, patchouli oil, lavandin oil, neroli oil, ylang oil, rose absolute or jasmin absolute; natural resins such as labdanum resin or olibanum resin; single perfumery chemicals which may be isolated from natural sources or manufactured synthetically, as for example alcohols such as geraniol, nerol, citronellol, linalol, tetrahydro- geraniol, betaphenylethyl alcohol, methyl phenyl carbinol, dimethyl benzyl carbinol, menthol or cedrol; acetates and other esters derived from such alcohols; aldehydes such as citral, citronellal, hydroxycitronellal, lauric aldehyde, undecylenic aldehyde, cinnamaldehyde, amyl cinnamic aldehyde, vanillin or heliotropin; acetals derived from such aldehydes; ketones such as methyl hexyl ketone, the ionones and the methylionones; phenolic compounds such as eugenol and isoeugenol; synthetic musks such as musk xylene, musk ketone and ethylene brassylate; and other materials commonly employed in the art of perfumery. Typically at least five, and usually at least ten of such materials will be present as compounds of the active ingredient.
Particularly preferred odiferous ingredients of blending into the novel compositions of our invention include geraniol, phenyl ethyl alcohol, citronellol hydroxycitronellal, ionones and methyl ionones, eugenol, isoeugenol, amyl and hexyl cinnamic aldehydes, methyl nonyl acetaldehyde, lemon oil, orange oil and bergamot oil.
The compounds of the formula I blend readily with other conventional ingredients of a compounded perfumery composition. They may be present as a major or a minor ingredient of such compositions but in general they will comprise from 0.5 to 10.0 preferably from 1.0 to 5.0% by weight of the compounded composition.
The preferred compound for present use is the dihydropyran. A mixture of its cis and trans isomers e.g. mixtures comprising from 10 to 90% say from 25 to 75% especially 40 to 60% of the trans isomer exhibit especially attractive odours and are therefore preferred for present use.
The use of the dioxan in isolation as an ingredient of a compounded perfumery composition is less preferred. However, the odours of the dihydropyran and the dioxan compliment one another and the use of a mixture of these two compounds as an ingredient of a compounded perfumery composition represents a preferred aspect of our invention. Such mixtures may for example comprise 10 to 90 mole percent e.g. from 25 to 75 mole percent most preferably from 40 to 60 mole percent of the dihydropyran.
Mixtures of the cis and trans dihydropyran which comprise at least 10% by weight of the trans isomer are believed to be novel.
Preferably at least 25% and more preferably at least 40% by weight of this compound is present in the form of the trans isomer.
The compounds which are useful according to our invention may conveniently be prepared by means of a Prins reaction between allo-ocimene and formaldehyde. For reasons of convenience we prefer to react allo-ocimene with paraformaldehyde rather than formaldehyde itself.
The reaction may conveniently be carried out in a suitable solvent in which the paraformaldehyde is soluble. The use of solvents which tend to cause polymerisation of the allo-ocimene e.g. protonic solvents is less preferred and should be avoided if possible. Preferred solvents for present use are methylene chloride, glacial acetic acid and chloroform.
The reaction is preferably carried out by mixing an excess e.g. from 1.0 to 4.0 moles of allo-ocimene per mole of formaldehyde with the formaldehyde and the solvent.
The reactants are preferably maintained at a temperature of from 20° to 120°C, more preferably 40 to 65°C for a period of from 2 to 40 say 4 to 30 hours.
The reaction may be carried out in the presence of a catalyst such as a Lewis acid. The preferred catalysts for present use are stannic chloride and boron trifluoride. The preferred solvents for the catalysed reactions are those in which the catalysts is soluble e.g. chlorinated hydrocarbons such as chloroform. The catalysed reaction may conveniently be carried out at lower temperatures of from 0 to 60° preferably 20 to 40°C the reactants being maintained at temperatures for a period of from 1 to 24 hours the short timers referring to the higher temperatures. The use of such catalysts for the reaction is generally less preferable because of the increased tendency of the allo-ocimene to polymerise. Preferably where. it is used the catalysts will be added in just sufficient a quantity as to be effective in catalysing the Prins reaction in order to minimise this tendency.
The product of the reaction is worked up using the conventional techniques of synthetic organic chemistry. The volatile fraction which can be separated by distillation comprises unchanged allo-ocimene, the dihydropyran and the dioxan together with a mixture of three triene alcohols. These triene alcohols are novel and find use as intermediates in the preparation of dihydropyrans and dioxans. These triene alcohols are:

2,7-dimethyl-3-methylene-octa-4(trans)-6-diene-ol;
2,3,7-trimethyl-octa-3(trans)-5-(trans)-7-triene-1-ol and
2,3,7-trimethyl-octa-3(cisl-5(trans)-7-triene-1-ol.

The components of the volatile fraction can be separated by fractional distillation. The unreacted allo-ocimene is normally separated from the other components. It may be convenient or preferably to utilise the remaining product mixture directly as an ingredient of a compounded perfumery composition.
The composition of this mixture is influenced by the conditions under which the reaction is carried out. In particular the greater the mole ratio of allo-ocimene to formaldehyde the greater the proportion of dihydropyran which is produced. The formation of the dihydropyrans is also favoured by the utilisation of an allo-ocimene feedstock which contains an increased proportion of the 4E6E isomer.
We have also discovered that it is possible to convert the dioxans and triene alcohols to the dihydropyrans by heating them in a polar protic solvent.
The dioxans and triene alcohols are preferably produced by the Prins reaction of formaldehyde and allo-ocimene as hereinabove described. (They may be separated from the other products of the Prins reaction prior to their conversion to dihydropyrans). The reaction is preferably carried out by heating the dioxans and/or triene alcohols to a temperature of from 50 to 100°C.
We have also discovered the cis dihydropyran may be converted into its trans isomer. This conversion may be carried out by heating a dihydropyran comprising less than 50% of the trans isomer in a polar protic solvent or by treatment at room temperature with a Lewis acid. These conversions processes lead to the formation of an equilibrium mixture comprising 50% of the trans isomer. The preferred conversions may be carried out at a temperature of from 50 to 100°.
This invention is illustrated by the following examples.

Example I

A compounded perfumery composition suitable for extrait use (all parts by weight).

Example II

A compounded perfumery composition suitable for extract use (A11 parts by weight).

Example III

A compounded perfumery composition suitable for use as a base in cosmetic preparations.

Example IV

Claims

1. A compounded perfumery composition which comprises a plurality of known odiferous ingredients together with at least one compound having the formula 1

wherein X may represent an oxygen atom in which case R₁ represents 4-methyi-penta-1,3, dien-1-yl group and R₂ represents a hydrogen atom or X may represent a methinyl group which is doubly bonded to C, in which the case R, disappears and R₂ represents a 2-methyl-prop-1-en-1-yl group.

2. A composition according to claim 1 which comprises a mixture of compounds of formula 1 consisting of from 25 to 75 mole percent of the compounds wherein X represents a methinyl group in admixture with the compounds, wherein X represents an oxygen atom.

3. A composition according to claim 1 which comprises a compound of formula 1 wherein X represents a methinyl group.

4. A composition according to claim 3 which contains a mixture of the cis and trans isomers of the compound of formula 1 wherein X represents a methinyl group.

5. A composition according to claim 4 which comprises from 25 to 75% of the trans isomers.

6. A composition according to any of the preceding claims which comprises from 0.5 to 10.0% by weight of said compounds of the formula 1.

7. A composition according to any of the preceding claims characterised in that it comprises at least one odiferous ingredient selected from known geraniol, phenyl ethyl alcohol, citronellol, hydroxycitronellal, ionones and methyl ionones, eugenol, isoeugenol amyl and hexyl cinnamic aldehydes, methyl, nonyl acetaldehyde, lemon oil, orange oil and bergamot oil.

8. A composition according to either of claims 6 or 7 characterised in that it comprises at least five odiferous ingredients.