US3647847A - Isolongifolene esters - Google Patents

Abstract

NOVEL ISOLONGIFOLENE ESTERS OF THE FORMULA:

5-(R-COO-)-2,3,5,6,7,7A-HEXAHYDRO-2,7A-ETHANOINDENE

WHEREIN R IS A C1-C5 ALKYL GROUP ARE PREPARED BY ALLYLIC SUBTITUTION, E.G. OXIDATION, OF ISOLONGIFOLENE, FOLLOWED BY REPLACEMENT OF THE SUBSTITUENT BY AN RCO2- GROUP. SAID ESTERS HAVE VALUBLE PERFUMERY PROPERTIES PARTICULARLY AS REPLACEMENTS FOR VETIVEROL DERIVATIVES.

Description

lvlal'd'l 7, 1972 I 0 A T ETIAL 3,647,841

ISOLONGIFOLENE ESTERS Filed Sept. 24, 1969 QOQ'Q g ombmggag WAV UNICAM SP 200 5000 4000 WAVE NUMBER Q o o R o m 8 a N 2 EDN V1 1 INS N VH1 United States Patent C) US. Cl. 260 -489 2 Claims ABSTRACT OF THE DISCLOSURE Novel isolongifolene esters of the formula:

R-il-O wherein R is a C -C alkyl group are prepared by allylic substitution, e.g. oxidation, of isolongifolene, followed by replacement of the substituent by an RCO group. Said esters have valuable perfumery properties particularly as replacements for vetiverol derivatives.

This invention relates to perfumery compositions of the type where a number of odoriferous 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 fabrics, fibres or paper products, in order to provide them with agreeable olfactory properties. Thus such concentrates (as well as the aforesaid perfumed materials) are products of commerce and the perfumery concentrates may comprise a simple or complex mixture of individual perfumery compounds.

The sesquiterpane longifolene (I) is obtainable as a by-product in the refining of Indian oil of turpentine. It is known that it may be isomerised to isolongifolene (II) by a number of means, and isolongifolene may be subjected to controlled oxidation to yield a mixture of ketones having valuable perfumery properties. It is also known (see Tetrahedron Letters 8,417.424 (1964)) that one of these ketones, having the structure III may be reduced to give an epimeric mixture of alcohols of the general structure IV.

3,647,847 Patented Mar. 7, 1972 We have now found methods of forming esters of alcohols of the type IV to produce a series of novel esters which have further been discovered to be highly suitable for use in perfumery.

Accordingly, from one aspect, this invention provides isolongifolenyl carboxylate esters of the structure Where R is an alkyl group having 1 to 5 carbon atoms.

From a second aspect the invention provides compounded perfumery compositions comprising an isolongifolenyl carboxylate ester of the invention.

Longifolene may be isomerised to isolongifolene by methods known in terpene chemistry, e.g. by treatment below C. with acetic acid or another weak acid in the presence of a little sulphuric acid. or other strong protonating agent; or by the action of boron trifluoride etherate.

It has been found possible to prepare the novel esters from isolongifolene by a variety of routes which can be considered as falling into two classes, which, however, have the common characteristic that in each case a reactive substituent group is first introduced into the secondary carbon atom in the position a to the olefinic double bond of isolongifolene and by a further reaction or reactions the reactive substituent group is then replaced by a group of formula RC-O The first of these, Class A, comprises first oxidising isolongifolene in a controlled manner to produce a mixture comprising a ketone of the Formula III which is thereafter reduced to an alcohol of the Formula IV. This alcohol may then be esterified by known means to produce a novel ester of the invention.

The controlled oxidation of isolongifolene to a mixture of ketones is described for example in Tetrahedron 8, 42-48 (1960) and it may be accomplished by the action of an acidic solution of a hexavalent chromium compound; e.g. by chromium trioxide in a mixture of tertiary butanol, acetic acid and acetic anhydride; or by sodium dichromate in sulphuric acid and acetic acid. Altematively, a mixture of vanadium pentoxide and hydrogen peroxide in acetone might be used. Preferably the reaction mixture is maintained below 50 C. to prevent undue over-oxidation. Also the isomerisation and oxidation of longifolene is conveniently carried out without the isolation of the intermediate isolongifolene.

There are likewise a number of methods available for the reduction of the ketone III to the alcohol IV. Such methods will readily suggest themselves to organic chemists; they include reduction with lithium aluminium hydride as described in Tetrahedron Letters 8, 417-426 (1964), reduction with sodium borohydride in ethanol and Meerwein-Ponndorf reduction using aluminium isopropoxide in isopropanol. The alcohol 1V may then be esterified by known means such as by treatment with the appropriate carboxylic acid in the presence of a trace of acidic catalyst such as sulphuric or hydrochloric acid or by treatment with the acid chloride or mixture of acid chloride and acid anhydride.

The second Class B, of possible routes from isolongifolene to the novel isolongifolenyl esters of the invention embraces a number of reactions for achieving this transformation, either directly or through the formation of other intermediates. For instance, isolongifolene may be subjected to allylic chlorination e.g. by reaction with chlorine in the presence of sodium carbonate the resulting chloroisolongifolene then being converted to the desired ester by replacement reaction, e.g. by reaction with the sodium salt of the appropriate carboxylic acid in the presence of a tertiary amine such as triethylamine. Alternatively isolongifolene may be treated with an organic peroin'de such as tertAbutyl hydroperoxide, cumene hydroperoxide, di-tert-butyl peroxide or ter.-butyl-perbenzoate, in the presence of cuprous chloride and the appropriate carboxylic acid; or, where the acetate is required it may be treated with lead tetra-acetate or mercuric acetate, again in the presence of the carboxylic acid, i.e. acetic acid. In all such reactions it will generally be necessary simply to stir the reactants together for as long as is found necessary to produce the maximum or optimum yield.

The group R in the compounds of the invention is an alkyl group containing from one to five carbon atoms. Appropriate carboxylic acids for use in the formation reactions mentioned therefore include acetic, propionic, butyric, pentanoic and hexoic acids. The preferred ester is the acetate, that is where R is methyl.

It will, of course, be normally necessary to carny out a purification procedure after preparation of the novel esters and possibly also at one or more intermediate stages in the case of Class A reaction sequence. Such procedures may vary according to the impurities involved but may generally comprise fractional distillation which has, in any case, been found a suitable method for effecting the final isolation and purification of the isolongifolenyl esters.

The aforesaid esters for present uses have a distinctive woody odour note somewhat akin to the esters of vetiverol which are expensive materials derived from vertiverol a constituent of vetivert oil. Accordingly, the compounded perfumery concentrates of the invention will often be formulated to take maximum advantage of this note and be similar to the formulations wherein the vertiverol esters have found use or would have found use if it had not been for their high price. Thus it is preferred that the esters be blended with one or more ionone compounds, such as the -,8 and a-ionOnes, the n-methylionones and/or isomethylionones; and/or with musk compounds, such as musk ketone or ethylene brassylate, each of which may have been prepared synthetically or isolated from natural sources or used in combination with other ingredients in less refined extracts of natural origin.

The aforesaid esters will generally be used only in a small amount in perfumery compositions since even in such amounts the desirable woody note is manifested. Thus the compounded perfumery compositions of the invention will usually comprise from 0.1 to preferably 0.5 to 10%, by weight of the said esters based on the total weight of perfumery ingredients. However, the invention envisages the use of blends of the esters with at least one ionone and/or musk compound for subsequent incorporation into compounded perfumery compositions of more complex formulations. Indeed the perfumery compositions of the invention will often comprise a considerable number of perfumery components. The blends of the esters of the invention with ionone and/or musk compounds may comprise, for example up to 60% by weight of the novel esters. Moreover, the novel esters have been found to blend particularly satisfactorily with vertiveryl acetate, vetiverol, vetivert oil, sandalwood oil, cedarwood oil, labdanum oil, oakmoss oil and patchouli oil. Blends of isolongifolenyl esters of the invention with any of these aforesaid compounds are included within the scope of the invention.

The compounded perfumery compositions of the invention find use in a wide variety of perfumed materials, for example, the compositions may find particular use in contourier-type perfumes, cologne or toilet waters, space sprays or they can be blended in soap, detergent or deodorant compositions including bath salts, shampoos, or in cosmetic preparations, such as face creams, talcum powders, body lotions, sun cream preparations and particularly, because of the nature of their perfumery note, in male toilet products such as shave lotions and creams. The compositions can also be used to perfume substrates such as fibres, fabrics and paper products.

The invention will now be illustrated by the following examples wherein all quantities are expressed on a weight basis. Examples 1-3 describes various methods of preparing the novel isolongifolenyl esters whilst Examples 4 to 6 describes novel perfumery compositions of the invention.

EXAMPLE 1 Isolongifolene (102 gms.), acetic acid (100 mls.) and cuprous chloride (0.2 gm), were introduced into a 500 ml. flask fitted with a stirrer. The flask was heated to C. and 49 grams tert.-butyl perbenzoate added over two hours. The mixture was heated at 80 C. or afurther 8 hours and then diluted with petroleum ether and washed consecutively with water, sodium carbonate solution (10%) and water. The extract was allowed to stand over anhydrous sodium sulphate over night and the petroleum ether was removed by evaporation over a steam bath. Distillation of the oil yielded a mixture of isolongifolenyl acetates having an infra red spectrum as shown in FIG. I and the following characterising data:

Refractive Index at 25 C.--1.5000 Density at 25 C.1.0l08 gs./cc. Boiling point at 2 mm. mercury pressure-ca. 131 C.

Saponification of 5 grams of the acetate mixture produced as above, using a solution of sodium hydroxide in aqueous ethanol, yielded 3 grams of a mixture of alcohols having a refractive index of 1.5099 at 25 C.

EXAMPLE 2 Isolongifolene (204 'gms.) and anhydrous sodium oarbonate (80 gms.) were placed in a 500 mls. flask fitted with a stirrer and cooling jacket. Chlorine was slowly passed into the mixture at such a rate that the temperature was maintained below 30 C. When the chlorination was finished the isolongifolenyl chlorides produced were filtered free from the inorganic salts.

The chlorides were then placed in a 2 l. flask fitted with a stirrer and were heated with acetic acid (1.000 ml.) and sodium acetate (100 gms.) for 48 hours at 80 C.

The mixture was diluted with water and extracted with petroleum ether. The combined extracts were washed with water, sodium bicarbonate solution 10%) and again with water. The resulting petroleum ether extract was then dried over anhydrous sodium sulphate and the solvent removed by evaporation over a steam bath. Distillation of the oil yielded a mixture of acetates as in Example 1.

EXAMPLE 3 Isolongifolene (750 mls.) and cuprous chloride (2 gms.) were placed in a 2 l. flask fitted with a stirrer. The flask was heated to C. A mixture of acetic acid gms.) and t.-butyl hydroperoxide (100 gms.) was slowly added over 2 hours. The mixture was stirred for a further 16 hours at 80 C. After cooling the oil was washed twice with water, once with 10% sodium carbonate and once with water. Distillation yielded unchanged isolongifolene and a mixture of acetates, as in Example 1.

EXAMPLE 4 A Woody base suitable for incorporation into a wide variety of perfumery compositions in concentrations ranging from 0.1% to 20% of the compounded composition was prepared from the following ingredients:

Parts Cedarwood oil (American) 500 Isolongifolenyl acetate 200 Olibannm Resin 50 Methyl ionone O Vetivert oil (Bourbon) Coumarin 20 Bois de Rose Oil 10 Patchouli Oil (Penang) 10 Sandalwood Oil (East Indian) 10 EXAMPLE 5 A spruce type fragrance suitable for use in a wide variety of perfumed materials, for example bath preparations, was prepared from the following ingredients:

The last compound, ionone cyclic ether, is a benzopyran of the formula wherein the unsatisfied carbon valencies are filled by hydrogen atoms, according to the conventional nomenclature. These compounds may be prepared by isomerisation of p-ionone.

EXAMPLE 6 A modern perfume suitable for use in aldehyde soaps was prepared from the following ingredients:

Parts Cinnamyl alcohol 150 Benzyl alcohol 100 Amyl salicylate 100 Benzyl salicylate 70 Methyl ionone 65 Amyl cinnamic aldehyde Isolongifolenyl acetate 50 Phenyl ethyl alcohol 50 Hydroxycitronellal 50 Musk ketone 30 Ver salide 3O P-isopropyl alpha methyl hydrocinnamic aldehyde 30 Coumarin 20 Benzyl acetate 20 P-tert.-butylcyclohexyl acetate 20 Vetivert oil (Bourbon) 20 Geranyl acetate 20 Civet (synthetic) l0 Decyl alcohol 10 Lauryl alcohol 5 Lauryl aldehyde 2 Methyl nonyl acetaldehyde 2 Decyl aldehyde 2 Iso-Jasmone 2 Methyl salicylate 2 Allyl caproate 2 Methyl heptine carbonate 1 We claim: 1. A compound having the structure:

0 R-il-O wherein R is an alkyl group containing from 1 to 5 carbon atoms.

2. The compound according to claim 1 wherein R is methyl.

References Cited Chem. Abstracts, 49: 123863 60: 1617d, 62: 16305d.

JAMES A. PATIEN, Primary Examiner V. GARNER, Assistant Examiner US. Cl. X.R.

252522; 260-488 B, 497 R, 587, 631.5, 648 C, 675.5

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