Unilever Patent Holdings B.v.

Quest International B.v.

Givaudan S.a.

Quest International Services B.v.

Christopher P Newman

Paul Nicholas Davey

Karen Jane Rossiter

Simon Ellwood

Keith Robert Motion

Charles S Sell

Chi-Lam Tse

Stephen E Meakins

Graham Patrick Vennall

Clive Derek Richardson

Barrie R Hart

Paul Nicolas Davey

Clive D Richardson

Brian J Hardinge

Terence L Miller

Varinder Kumar Aggarwal

William Alexander Thiam

Jan Thomas Haines

Martin Schroeder

Pietro Tundo

A process of preparing cyclic ethers is described. The process involves the reaction of at least one organic compound such as a dioi or a polyol which it has at least one pair of hydroxyl groups separated by 4 or 5 carbon atoms, and which is capable of being converted into an ether linkage, with an organic carbonate in the presence of a base. The base is an alkoxy, a carbonate or a hydroxide base or is a mixture of such bases. At least one of the hydroxyl groups of the organic compound is not a tertiary hydroxyl group.

Cyclic ethers

A method of making a 3-alkylcycloalkanol of formula 2: where Rrepresents a methyl or ethyl group, Rrepresents hydrogen, Rrepresents an ethyl, propyl, butyl, isobutyl or isoamyl group, Rrepresents hydrogen and Rrepresents hydrogen, or a methyl, ethyl, propyl, isobutyl or isoamyl group comprises the following steps: (1) carrying out an electrophilic substitution reaction of an alkyl group or precursor thereof, on an ortho-substituted alkylbenzene compound of formula 3: where Rrepresents hydrogen, or a methyl or ethyl group; (2) hydrogenating the reaction product of step (1); (3) performing an elimination reaction on one or more reaction products of step (2) to produce one or more alkene products; and (4) hydrating the one or more alkene products of step (3) to provide a 3-alkylcycloalkanol of formula 2. The electrophilic substitution reaction of step (1) may be a Friedel-Crafts acylation, e.g. using an isopropyl ketone precursor, or a Friedel-Crafts alkylation, e.g. using an isobutyl group. The 3-alkylcycloalkanols, especially 3-(2-methylpropyl)-1-methylcyclohexanol, are useful fragrance materials and find use in perfumes and perfumed products.

Production of 3-alkylcycloalkanols

A process for the preparation of carvone comprises hydrogenating carvoxime in the presence of a selecively poisoned catalyst. Preferred catalysts include noble metals supported on inorganic materials poisoned with a catalyst modifier. In a preferred embodiment of the process defined herein, the crude carvone reaction product produced in accordance with the process of the invention, is purified by treating the crude carvone product with an organometallic compound M(X) wherein M is a polyvalent metal, n is the valence of M and X denotes an inorganic or organic atom or group.

Preparation of carvone

The invention concerns Diels-Alder reactions between non-activated aldehydes RCHO in which R is a C1-C10 aliphatic group or phenyl group, which is unsubstituted or substituted with one or more C1-C5 alkyl groups or one other functional group, with simple aliphatic dienes R.sub.1 CH.dbd.CR.sub.2 --CR.sub.3 .dbd.CHR.sub.4 in which R.sub.1 -R.sub.4 are H or C1-C5 alkyl groups using as a catalyst a perfluorinated organic sulphonic acid or a Bronsted acid derivative thereof. The reaction leads to dihydropyrans of the structure below in which R1-R4 have the meaning indicated above. The preferred perfluorinated organic sulfonic acids are perfluorooctanesulphonic acid, triflic acid, Nafion or a Bronsted acid derivative of triflic acid. ##STR1## The preferred aldehydes are those wherein R is a C2-C6 aliphatic group or a phenyl group which is unsubstituted or mono-substituted with C1-C3 alkyl or with 4-Cl, 4-nitro or 3-methoxy. The preferred dienes are those wherein the groups R.sub.1 -R.sub.4 are H or methyl.

Diels-alder reaction of aldehydes with simple dienes

Dihydromyrcene is reacted with a carboxylic acid, eg acetic acid, to produce an ester which is then reacted with an alcohol in a transesterification reaction to produce (dihydro)myrcenol and another ester. The preferred alcohol is 4-tertiarybutylcyclohexanol. Myrcenol can be produced in a similar way.

Transesterification process

The invention relates to the preparation of ceramides by a two step process involving conversion of a 2-hydroximino-3-oxo-alkanoate into a 2-alkanoylamido-3-oxo-alkanoate intermediate by acylation of the oxime and reduction of the oxime ester group to an amido group, followed by reduction of the keto and ester group of the intermediate to the 1,3 diol of the ceramide. The oxime acylation and the first reduction may be carried out consecutively or simultaneously. The first reduction is preferably a catalytic hydrogenation and the second reduction is preferably a borohydride reduction. The invention further relates to novel 2-alkanoylamido-3-oxo-alkanoates and 2-alkanoyloximino-3-oxo-alkanoates which are useful as intermediates for conversion into ceramides.

Process for the preparation of ceramides

A method of acetylating 1,2,3,4,-tetrahydro-1,1,2,4,4,7-hexamethylnapthalene (HMT) to produce 6-acetyl-1,2,3,4-tetrahydro-1,1,2,4,4,7-hexamethlnaphthalene (acetyl-HMT), comprises subjecting a mixture of 1,2,3,4-tetrahydro-1,1,2,4,4,7-hexamethlnaphthalene and or one or more substituted indanes or substituted acetylindanes to a Friedel-Crafts acetylation reaction in the presence of a saturated hydrocarbon solvent.

Acylation of tetralins

The invention relates to a process for the conversion of 8-hydroxymenthenes into 8-hydroxycymenes by treating the 8-hydroxymenthenes in the vapour phase with an alkaline dehydrogenation catalyst, e.g. palladium on an alkaline support. The process is carried out above 145.degree. C. The hydroxymenthene vapour is preferably passed through the catalyst system at a pressure below 8 kPa and/or with the aid of an inert gas or vapour. Oxygen may be present as a hydrogen acceptor. The process is particularly suitable for converting 8-hydroxy-p-menth-1-ene into 8-hydroxy-p-cymene. The reaction products are of value as intermediates in the preparation of musk fragrance chemicals.

8-hydroxycymene preparation by dehydrogenation

Novel perfumery chemicals having a cyclic acetal structure and providing a variety of perfume notes, especially amber, are described. They are prepared by reacting specified diols and aldehydes/ketones.

Perfumery materials

The invention relates to a process for the conversion of 8-hydroxymenthenes into 8-hydroxycymenes by treating the 8-hydroxymenthenes in the vapor phase with a dehydrogenation catalyst, e.g. palladium. The process is preferably carried out at 80.degree.-150.degree. C. The hydroxymenthene vapor is preferably passed through the catalyst system at a pressure below 8 kPa and/or with the aid of an inert gas or vapor. Oxygen may be present as a hydrogen acceptor. The process is particularly suitable for converting 8-hydroxy-p-menth-l-ene into 8-hydroxy-p-cymene. The reaction products are of value as intermediates in the preparation of fragrance chemicals.

Cymenol preparation by direct dehydrogenation

Process for preparing an alkyl substituted tetralin or indane by reacting a benzyl alcohol with an alkene having 4-7 carbon atoms under the influence of a Lewis acid catalyst. The product can be further reacted with an acyl halide or alkylene epoxide without prior isolated from the initial reaction mixture.

Process for the preparation of alkyl substituted tetralins and indanes

The invention relates to a process for the conversion of 8-hydroxymenthenes into 8-hydroxycymenes by reacting the 8-hydroxymenthenes in the liquid phase in the presence of a dehydrogenation catalyst, e.g. palladium and a hydrogen acceptor e.g. mesityl oxide. The process is preferably carried out at 80.degree.-150.degree. C. and in the presence of base. The process is particularly suitable for converting 8-hydroxy-p-menth-1-ene into 8-hydroxy-p-cymene. The reaction products are of value as intermediates in the preparation of fragrance chemicals.

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Canterbury, United Kingdom

Christopher P Newman