COMPOUNDED PERFUMERY COMPOSITION

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: This invention relates to compounded perfumery compositions to ingredients of such compositions certain of which are believed to be novel and to processes for the preparation of these ingredients and novel intermediates for use in these processes. 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 hydrocarbons. 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 paraformaldehyde in dichloromethane under reflux in the presence of acetic acid has been reported In Nippon Kagaku Kaishi 1977 (8) pl253-5. The product of this reaction is reported to comprise a mixture of a dihydropyran having the formula: EMI2.1 and the cis and trans isomers of a dioxan having the formula: EMI2.2 These compounds have now been discovered to possess attractive floral odours. Thus from one aspect our invention provides a compounded perfumery composition which comprises a plurality of odoriferous ingredients together with at least one compound having the formula I: EMI3.1 wherein X may represent an oxygen atom in which case R1 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 C1 and singly bonded to C2 in which case R1 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 essential 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, ltnalol, tetrahydrogeraniol, betaphenylethyl alcohol, methyl phenyl carbinol, dimethyl benzyl carbinol, menthol or cedrol; acetates and other esters derived from such alcohols; aldehydes such as citral, citronellal, hydroxy-citronellal, 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 60X 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 per cent 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. Thus from another aspect our invention provides a compound of the formula EMI5.1 wherein at least 10% of said compound is present in the form of the trans isomer. Preferably at least 25% and more preferably at least 40% 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 alloocimene and formaldehyde. For reasons of convenience we prefer to e 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 formaldehye with the formaldehyde and the solvent. The reactants are preferably maintained at a temperature of from 200 to 1200C, more preferably 40 to 650C 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 600 preferably 20 to 4O0C 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 alloocimene, 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 od dihydropyrans and dioxans. Thus from another aspect our invention provides the triene alcohols 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 (cis) - 5 (trans) - 7 - triene-1-ol. The components of the volatile fraction can be separated by frational 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 mxiture 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. Thus from another aspect our invention provides a process for the preparation of a compound of the formula: - EMI8.1 which comprises heating a dioxan or a triene alcohol as hereinbefore -defined in a polar protic solvent. The dioxans and triene alcohols are preferably produced by the Prins reaction of formaldehyde and allo-ocimene as hereinabefore 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 1000C. 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 1000. This invention is illustrated by the following examples. EXAMPLE ONE 1.2 kg (8.8 moles) of allo-ocimene 250 gram (8.3 moles) of paraformaldehyde and 1 litre of glacial acetic acid were mixed and maintained at a temperature of from 45 to 600C for a period of 47 hours. The allo-ocimene had a E,Z ratio of 73.5:26,5. Thereafter, acetic acid was distilled off using an oil pump whilst maintaining the reaction mixture of a temperature of less than 450C. About 1 litre of a distillate comprising acetic acid and some unreacted allo-ocimene was removed. The residue was washed three times with water, once with a 5% sodium carbonate solution dried over sodium sulphate and filtered to give 1,386 gram of a yellow liquid product. This product was then fractionally distilled under reduced pressure using a 30 cm Fenske column In order to remove unreacted allo-ocimene. 411 grams of material were removed the bulk of which was allo-ocimene. The residue was then distilled after removal of the column to give 195 gram of a product (obtained under pressure of 0.9 mm Hg; Pot temperature 72-920C, still head temperature 56750C) which was shown to comprise the dihydropyran of Formula I by GLC analysis. This product had an attractive rose odour with a distinct metallic note. EXAMPLE TWO Alloocimene (45% 4E 6Z, 55X 4E 6E) 12 grams (0.088 moles) was added to a stirred suspension of paraformaldehyde (4.09, 0.133 moles) in methylene chloride (40 mls) with glacial acetic acid (10 mls). The reaction was stirred for 31 hours at methylene chloride reflux temperature (420C). Excess dimethyl ether was then added to the cooled product mixture. The organic layer was washed with water, dilute sodium hydroxide solution and again with water. After drying over anhydrous sodium carbonate the organic layer was stripped of solvents and then micro-distilled under vacuum to remove high boiling polymeric product. The volatile product, 10g, had the following composition by GLC (9'leo% Sip2100 on 80/100 supelroport at 140C with Flame Ionisation Detector): Alloocimene 4E 6Z 30% 4E 6E 18% Dihydro Pyrans cis 26% trans 1% Alcohols 2% Dioxans trans 8% cis 15% EXAMPLE THREE Alloocimene, 45% 4E 6Z, 55% 4E 6E, (2kg, 14.7 mol) was added to a stirred suspension of paraformaldehyde, 400 gm 13.3 moles, in glacial acetic acid 1500 ml. The reaction mixture was stirred for 30 h within the temperature range 40 to 450C. After cooling, a small amount of residual paraformaldehyde was filtered out and the filtrate water washed to extract acetic acid. The oil was then distilled under vacuum to remove high boiling polymeric product. The volatile product 1967g, had the following composition by GLC (9'it% SP 2100 on supelcoport at 14O0C with Flame Ionisation Detector). Alloocimene 4E 6Z 27% 4E 6E 18% Dihydro Pyrans cis 22% trans 2% Alcohols 3% Dioxans trans 10% cis 19% Fractionation of this product gave: Recovered allocimene, b.p., 73-77/6 mm Hg 6809 Dihydropyrans, b.p., 84-860C/mm Hg 6009 Dioxans, b.p., 80-85 C/0.2mm Hg 5379 Mixed dioxans/alcohols b.p. 85-900C/0.2mm Hg 809 The last three fractions were combined to give a product with a rounded floral rose odour with a sweet citrus dry out. EXAMPLE FOUR Alloocimene (45% 4E6Z, 55% 4E6E) 2kg, 14.7 moles was added to a stirred suspension of paraformaldehyde (425g 14.1 moles) in glacial acetic acid (1500 ml). The reaction mixture was stirred for 30 hours within the temperature range 55 to 600C. After 12 hours all the paraformaldehyde had dissolved in the reaction medium. After cooling, the reaction mixture was water washed to extract acetic acid. The oil was then distilled under vacuum to remove high boiling polymeric product. The volatile product, 16509, had the following composition by GLC (9'10% SP2100 on 80/100 supelcoport at 1400C with Flame Ionisation Detector): Alloocimene 4E 6Z 23% 4E 6E 19% Dihydro Pyrans cis 20% trans 7% Alcohols 10% Dioxans trans 9S cis 13% Non volatile residue constituted 25% of the charge for distillation. The cis and trans isomer of the dihydropyran were separated by spinning band fractionation. The cis isomer had fresh-rose odour with a hint of greenness. The trans isomer had a floral metalic rose character. The two isomers were combined to give a product with a fresh floral metallic rose character. EXAMPLE FIVE Alloocimene (96% 4E6E), 1609 1.18 moles, was added to a stirred suspension of paraformaldehyde (24g, 0.8 mole) in glacial acetic acid (120 ml). The reaction mixture was stirred for 5 hours within the temperature range 55 to 5O0C. After cooling, the reaction mixture was water washed to extract acetic acid. The oil layer was then distilled under vacuum to remove high boiling resinous product. The volatile product, 1509, had the following composition by GLC. (9'10% SP2100 on 80 to 100 supelcoport with Flame Ionisation Detector): Alloocimene 4E 6E 45% Dihydropyran cis 33X trans 2% Alcohols 3% Dioxan trans 4% cis 10% Ratio of Pyrans: Dixons was 2.5. EXAMPLE SIX Stannic chloride (0.1 ml) was added dropwise to a stirred suspension containing alloocimene, 85% 4E6Z 15% 4E6E, (2)9, 0.15 mole) paraformaldehyde (4.59, 0.15 mole) and anhydrous chloroform (150ml). The mixture was stirred at room temperature for 28 hours and then filtered to remove a small amount of unreacted paraformaldehyde. The filtrate was washed twice with 5% sodium carbonate solution (100 ml) and then dried over sodium sulphate. Distillation gave 169 volatile product containing: Alloocimenes 4E 6E) 15% 4E 6Z) Dihydropyrans cis 32% trans 29% Dioxans trans 10% cis 10% EXAMPLE SEVEN lOgm cis dihydropyran was refluxed and stirred with an aqueous solution containing 10% acetic acid (10ml) for 2 hours. Separation of the oil layer followed by micro distillation gave 8g of volatile product containing: cis dihydropyran 50% trans dihydropyran 35% triene alcohols 15% EXAMPLE EIGHT 10g cis and trans dioxans were refluxed and stirred with an aqueous solution containing 5% acetic acid (10ml) for 2 hours. Separation of the oil layer followed by micro distillation gave 9g of volatile product containing: cis dihydropyran 20X trans dihydropyran 16% triene alcohols 16% Dioxans 48% EXAMPLE NINE A compounded perfumery composition suitable for extrait use (all parts by weight). 4 Acetyl 6. tertiary Butyl 11. Dimethyl Indan 2.04 Cyclo Pentadecanolide 2.04 Benzyl Salicylate 4.08 Iso Butyl Sallcylate 2.04 Phenyl ethyl Alcohol 8.16 Acetyl Cedrene 3.06 Aldehyde C.10 0.20 Aldehyde C.11 Undecylenic 0.71 Aldehyde C.12 Lauric 0.51 Ambrette Seed Oil 0.51 Bergamot Oil Bergapteneless 3.06 Bois de Rose Oil 3.06 Clove Absolute 0.51 Ethyl Vanillin 10% Soln. in D.E.P. 0.51 Galaxolide 50 3.57 Geraniol 5.71 Geranium Oil Bourbon 1.53 Hexyl Cinnamic Aldehyde 6.55 Jasmal 3.06 Jasmin Absolute 6.12 Cis Jasmone 0.51 Labdanum Caste Absolute 10% Soln. in D.E.P. 0.82 Lilial 6.12 Lyral 3.06 Methyl Dihydro Jasmonate 3.27 Methyl Ionone 7.67 Methyl Phenyl Carbinyl Acetate 0.82 Oakmoss Absolute 50% Soln in D.E.P. 1.02 Orris Resin 10% Soln. in D.E.P. 0.51 Rose Absolute 7.14 Sandalwood Oil Mysore 4.08 Tagete Oil 0.20 Continued Verbena Oil French 0.51 Vetivert Oil 1.12 Vetiveryl Acetate 3.06 Ylang Oil 2.04 Dihydropyran (Product of Example 4) 1.02 100.00 EXAMPLE TEN A compounded perfumery composition suitable for extract use (All parts by weight). Musk Ambrette 5.25 Musk Ketone 1.50 Benzyl Sal icyl ate 14.37 Phenyl Ethyl Alcohol 3.25 Acetyl Cedrene 2.35 Aldehyde C.11 Undecylenic 0.34 Aldehyde C.12 (Methyl Nonyl Acetaldehyde)10% Soln.in D.E.P. 0.85 Amyl Cinnamic Aldehyde 1.80 Bergamot Oil Bergapteneless 5.56 Coriander Oil 1.71 Eugenol 2.35 Iso Eugenol 1.71 Eugenyl Acetate 0.85 Galaxolide 50 1.71 Geranium Oil Bourbon 0.43 Geranyl Nitrile 0.43 Hydroxycitronel 1 al 3.44 Jasmal 1.71 Continued Jasmine Absolute 5.97 Lemon Oil 2.56 Lilial 5.12 Li nalol 2.56 Linalyl Acetate 5.12 Mandarin Oil 2.99 Methyl Ionone 5.97 para Methyl Phenyl Acetaldehyde 0.68 Methyl Phenyl Carbinyl Acetate 0.75 Olibanum Resin 0.43 Orange Flower Absolute 10% Soln.in D.E.P. 0.43 Orange Oil Sweedt 4.27 Phenyl acetal dehyde Dimethyl Acetal 0.43 Rose Absolute 2.73 Sandalwood Oil Mysore 3.41 Verbene Oil 0.85 Ylang Oil 2.73 Dihydropyran (Product of Example 4) 3.41 100.00 EXAMPLE ELEVEN A compounded perfumery composition suitable for use as a base in cosmetic preparations. 4 Acetyl 6.tertiary Butyl 11.Dimethyl Indan(Musk D.T.I) 0.15 Trichloro Methyl Phenyl Carbinyl Acetate 0.87 Dimethyl Phthdlate 6.08 Phenyl Ethyl Alcohol 70.13 Aldehyde C.9 0.18 Aldehyde C.11 Undecylenic 10% Soln.in D.E.P. 0.30 Iso Butyl Iso Butyrate 0.44 Carrot Seed Oil 0.12 Cassia Oil 10% Soln. in D.E.P. 0.08 Celery Seed Oil 0.06 Chamomile Oil English 0.06 Citral 0.29 Ci tronel lyl Acetate 0.73 Citronel lyl Butyrate 0.10 Iso Eugenol 0.15 Geraniol Pure 11.59 Geranium Oil Bourbon 0.87 Geranyl Butyrate 0.49 Guaiyl Acetate 1.17 Alpha Ionone 0.58 Lie de Vin Oil Green 0.06 n Octyl Acetate 0.06 Patchouli Oil French 0.29 Phenyl Ethyl Iso Butyrate 0.50 Sandalwood Oil Mysore 0.78 Rose de Mai Concrete 0.66 Violet Leaves Absolute 0.30 Dihydropyran/Dioxan mixture (Product of Example III) 2.91 100.00 EXAMPLE TWELVE Dimethyl Hydroquinone 0.46 Diphenyl Oxide 0.46 Musk Ambrette 2.17 Amyl Salicylate 17.80 Hydroxycitronellal 2.32 Phenyl Propyl Alcohol 4.41 Aldehyde C.12 Lauric 0.03 Amyl Cinnamic Aldehyde 4.41 Armoise Oil Tunisian 1.32 Iso Butyl Salicylate 0.85 Cedarwood Oil 13.44 Clary Sage Oil 4.64 Clove Bud Oil 10% Soln.in D.E.P. 0.77 Ethyl Methyl Phenyl Glycidate 10% Soln.in D.E.P. 0.04 Iso Eugenol 4.72 Galaxolide 50 0.39 Galbanum Resin 50% Soln. in D.E.P. 4.64 Geranyl Nitrile 0.15 Geranium Oil 0.77 Ci s-3-Hexenol 0.46 Hexyl Cinnamic Aldehyde 4.41 Hyssop Oil 1.76 Indolene 0.93 Labdanum Caste Absolute 0.02 Lemon Oil 1.55 Lilial 2.40 Linalolt 2.32 Methyl Ionone 4.95 Treemoss Absolute 50% Soln. in D.E.P. 0.77 Continued..... Olibanum Resin 1.94 Orange Oil Sweet 7.74 Patchouli Oil 0.77 Styrax Oil Totale 2.32 Ylang Oil Extract 2.32 Dihydropyran/Dioxan Mixture (Product of Example 3) 3.10 100.00

Claims: WHAT WE CLAIM IS:1. A compounded perfumery composition which comprises a plurality of odiferous ingredients characterised in that at least one compound having the formula I: EMI21.1 wherein X may represent an oxygen atom in which case R1 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 C1 in which case R1 disappears and R2 represents a 2-methyl-prop-1-en-1-yl group is present 2. A composition according to claim 1 characterised in that it comprises from 25 to 75 mole percent of the compound wherein X represents a methinyl group in admixture with the compound, wherein X represents an oxygen atom, 3. A composition according to claim 1 characterised in that X represents a methinyl group. 4. A composition according to claim 3 the compounds characterised in that X represents a methinyl group is present a mixture of its cis and trans Isomers. 5. A composition according to claim 4 characterised in that it comprises from 25 to 75% of the trans isomer. 6. A composition according to any of the preceding claims characterised in that it comprises from 0.5 to 10.0% by weight of said compounds of the formula I. 7. A composition according to any of the preceding claims characterised in that it comprises at least one odiferous ingredient selected from the group consisting of geraniol, phenyl ethyl alcohol, citronellol, hydroxycitronellal, ionones and methyl lonones, 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 other odiferous ingredients. 9. A compound of the formula I wherein X represents a methinyl group characterised in that it comprises at least 10% of the trans isomer. 10. A compound according to claim 9 characterised In that it comprises at least 25% of the trans isomer. 11. A process for the preparation of a compound having the formula I wherein X represents a methinyl group characterised in that it comprises heating a compound of the formula I wherein X represents an oxygen atom in an aqueous polar protic solvent. 12. A process for the preparation of a compound of the formula I wherein X represents a methinyl group characterised in that it comprises heating one or more triene alcohols selected from the groupconsisting of 2,7-dimethyl-3-methylene-octa-4(trans)-6 dien-1-ol,2,3,7-trlmethyl-octa-3(trans)-5(trans)-7-triene-1-ol- and 2,3,7, trimethyl-octa-3(cis)-5(trans)-7-triene-1-ol in a polar protic solvent. 13. A process according to either of claims 11 or 12 characterised in that the species being heated has been obtained by virtue of a Prins reaction between formaldehyde and allo-ocimene. 14. 2,7-dimethyl-3-methylene-octa-4(trans)-6-dien-1-ol. 15. 2,3,7 trimethyl-octa-3(cis)-5(trans)-7-triene-1-ol. 16. 2,3,7 trimethyl-octa-3(trans)-5(trans)-7-triene-1-ol. 17. A process for the production of the trans isomer of the compound of the formula I wherein X represents a methinyl group which comprises the isomerisation of the cis isomer. 18. A process according to claim 17 characterised in that said isomerisation effected by heating the cis isomer in a polar protec solvent at a temperature of from 50 to 100 C.

Inventors: BOTTEN, JACQUELINE ANN, FERBER, GERALD JOHN, MELLOR, MICHAEL
Applicants: BUSH BOAKE ALLEN LIMITED
Application year: 1980
Main classification: C11B9
IPC codes: A61K8, C07D319, C11B9, C07D309, A61Q13