Abstract: The presently claimed invention relates to a process for the recovery of 3-methyl-3-buten-1-ol from a stream obtained in the production of 3-methyl-3-buten-1-ol from 2-methylprop-1-ene and formaldehyde, by treating the stream with an amine catalyst.

Abstract: The presently claimed invention relates to a process for the recovery of 3-methyl-3-buten- -ol from a stream comprising (Z)-3-methylpent-2-ene-1,5-diol, (E)-3-methylpent-2-ene-,5-diol and 3-methylenepentane-1,5-diol by treating the stream with isobutene and water.

Abstract: The present invention provides a process for preparing an unsaturated alcohol of the formula (I), wherein one of R1 and R2 is preferably C2-C10-alkyl or C2-C10-alkenyl containing one double bond and the other one is preferably hydrogen or methyl; R3 is preferably hydrogen; which comprises subjecting an educt composition including at least 75% by weight of an unsaturated aldehyde of the formula (II) wherein R1, R2 and R3 preferably have the above defined meanings, to a hydrogenation in the presence of a catalyst and a tertiary amine; wherein the tertiary amine is used in an amount ranging from 0.001 to 0.7% by weight, based on the total amount of the liquid reaction mixture.

Abstract: The presently claimed invention relates to a process for the recovery of 3-methyl-3-buten- -ol from a stream comprising (Z)-3-methylpent-2-ene-1,5-diol, (E)-3-methylpent-2-ene-,5-diol and 3-methylenepentane-1,5-diol by treating the stream with isobutene and water.

Abstract: The presently claimed invention relates to a process for the recovery of 3-methyl-3-buten-1-ol from a stream obtained in the production of 3-methyl-3-buten-1-ol from 2-methylprop-1-ene and formaldehyde, by treating the stream with an amine catalyst.

Abstract: The present invention provides a process for preparing an unsaturated alcohol of the formula (I), wherein one of R1 and R2 is preferably C2-C10-alkyl or C2-C10-alkenyl containing one double bond and the other one is preferably hydrogen or methyl; R3 is preferably hydrogen; which comprises subjecting an educt composition including at least 75% by weight of an unsaturated aldehyde of the formula (II) wherein R1, R2 and R3 preferably have the above defined meanings, to a hydrogenation in the presence of a catalyst and a tertiary amine; wherein the tertiary amine is used in an amount ranging from 0.001 to 0.7% by weight, based on the total amount of the liquid reaction mixture.

Abstract: The present invention relates to a particularly economic overall method for producing menthol, specifically for producing optically active, essentially enantiomerically and diastereomerically pure L-menthol and racemic menthol, starting from the starting material citral which is available inexpensively on an industrial scale. The method has the following steps a.1) catalytic hydrogenation of neral and/or geranial to give citronellal, b.1) cyclization of citronellal to isopulegol in the presence of an acidic catalyst, c.1) purification of isopulegol by crystallization and d.1) catalytic hydrogenation of isopulegol to give menthol.

Abstract: The present invention relates to a process for the preparation of 2-substituted 4-hydroxy-4-methyltetrahydropyrans.

Abstract: The invention relates to a method for producing 2-substituted 4-hydroxy-4-methyltetrahydropyrans.

Abstract: The present invention relates to a process for the preparation of 2-substituted 4-hydroxy-4-methyltetrahydropyrans by reacting 3-methylbut-3-en-1-ol (isoprenol) with the corresponding alkenealdehydes in the presence of a strongly acidic ion exchanger with subsequent hydrogenation. Specifically, the present invention relates to a corresponding process for the preparation of 2-isobutyl-4-hydroxy-4-methyltetrahydropyran by reacting isoprenol with prenal, with subsequent hydrogenation.

Abstract: The invention relates to a method for producing 2-substituted 4-hydroxy-4-methyltetrahydropyrans.

Abstract: The present invention relates to a process for the preparation of 2-substituted 4-hydroxy-4-methyltetrahydropyrans.

Abstract: The present invention relates to a process for the preparation of 2-substituted 4-hydroxy-4-methyltetrahydropyrans by reacting 3-methylbut-3-en-1-ol (isoprenol) with the corresponding alkenealdehydes in the presence of a strongly acidic ion exchanger with subsequent hydrogenation. Specifically, the present invention relates to a corresponding process for the preparation of 2-isobutyl-4-hydroxy-4-methyltetrahydropyran by reacting isoprenol with prenal, with subsequent hydrogenation.

Abstract: Process for the preparation of 2-substituted 4-hydroxy-4-methyltetrahydropyrans of the formula (I) where the radical R1 is a straight-chain or branched alkyl or alkenyl radical having 1 to 12 carbon atoms, an optionally alkyl-substituted cycloalkyl radical having in total 3 to 12 carbon atoms or an optionally alkyl- and/or alkoxy-substituted aryl radical having in total 6 to 12 carbon atoms, comprising the reaction of 3-methylbut-3-en-1-ol of the formula (II) with an aldehyde of the formula (III) R1—CHO??(III), where the radical R1 has the same meaning as in formula (I) and where the reaction is carried out in the presence of water and in the presence of a strongly acidic cation exchanger, and then the isolation and/or the distillative separation is carried out in a dividing wall column or in an interconnection of (at least) two distillation columns in the form of a thermal coupling and one or more side take-off points at an absolute operating pressure of up to 500 mbar.

Abstract: The present invention relates to a process for the preparation of 2-substituted 4-hydroxy-4-methyltetrahydropyrans by reacting 3-methylbut-3-en-1-ol(isoprenol) with the corresponding alkenealdehydes in the presence of a strongly acidic ion exchanger with subsequent hydrogenation. Specifically, the present invention relates to a corresponding process for the preparation of 2-isobutyl-4-hydroxy-4-methyltetrahydropyran by reacting isoprenol with prenal, with subsequent hydrogenation.

Abstract: The present invention relates to an improved process for preparing a substituted or unsubstituted phenylcyclohexane by catalytic hydrogenation of a substituted or unsubstituted biphenyl.

Abstract: The present invention relates to a process for the preparation of 2-substituted 4-hydroxy-4-methyltetrahydropyranols by reacting 3-methylbut-3-en-1-ol (isoprenol) with the corresponding aldehydes in the presence of a strongly acidic cation exchanger. Specifically, the present invention relates to a corresponding process for the preparation of 2-isobutyl-4-hydroxy-4-methyltetrahydropyran by reacting isoprenol with isovaleraldehyde.

Abstract: The present invention relates to a continuous process for preparing racemic or optically active menthol in pure or enriched form by distillatively separating menthol from substance mixtures which comprise essentially menthol and diastereomers thereof. This distillatiive separation is performed in a dividing wall column with 50 to 300 theoretical plates and one or more side draw points at an absolute operating pressure of 5 to 500 mbar.

Abstract: The present invention relates to a particularly economic overall method for producing menthol, specifically for producing optically active, essentially enantiomerically and diastereomerically pure L-menthol and racemic menthol, starting from the starting material citral which is available inexpensively on an industrial scale. The method comprises the following steps a.1) catalytic hydrogenation of neral and/or geranial to give citronellal, b.1) cyclization of citronellal to isopulegol in the presence of an acidic catalyst, c.1) purification of isopulegol by crystallization and d.1) catalytic hydrogenation of isopulegol to give menthol.

Abstract: The present invention relates to a process for preparing 4,4?-[1-(trifluoromethyl)alkylidene]bis(2,6-diphenylphenols), in particular for preparing 4,4?-[1-(trifluoromethyl)ethylidene]bis(2,6-diphenylphenol), which comprises the self-condensation of cyclohexanone in the presence of a basic catalyst to form tricyclic condensation products, dehydrogenation of the resulting tricyclic condensation products in the presence of a supported transition metal catalyst in the condensed phase to form 2,6-diphenylphenol and reaction of the 2,6-diphenylphenol with a trifluoromethyl ketone. The invention further provides an improved process for preparing 2,6-diphenylphenol by aldol self-condensation of cyclohexanone.