Abstract: The present invention relates to a process for the preparation of cis-2-(2-methylprop-1-enyl)-4-methyltetrahydropyran comprising the catalytic hydrogenation of 2-(2-methylprop-1-enyl)-4-methylenetetrahydropyran in the presence of hydrogen and a heterogeneous catalyst comprising ruthenium on a support and subsequently bringing the compounds obtained in this way into contact with a strongly acidic cation exchanger.

Abstract: The present invention relates to a process for the preparation of cis-2-(2-methylprop-1-enyl)-4-methyltetrahydropyran comprising the catalytic hydrogenation of 2-(2-methylprop-1-enyl)-4-methylenetetrahydropyran in the presence of hydrogen and a heterogeneous catalyst comprising ruthenium on a support and subsequently bringing the compounds obtained in this way into contact with a strongly acidic cation exchanger.

Abstract: The present invention relates to a method of producing pure or enriched bisabolol by separating substance mixtures comprising bisabolol and farnesol by selective esterification of farnesol and subsequent distillative separation. The invention relates specifically to a method as specified above comprising the selective transesterification of mixtures comprising formyl-bisabolol and formyl-farnesol and subsequent distillative separation. The present invention furthermore relates to a method of producing farnesol esters.

Abstract: A process for obtaining oligomers of polytetrahydrofuran or of tetrahydrofuran copolymers from a methanolic crude product which contains polytetrahydrofuran or tetrahydrofuran copolymers and is obtained in the transesterification of the mono- and/or diesters of polytetrahydrofuran or tetrahydrofuran copolymers with methanol, which includes a) removing the majority of the methanol from the crude product in a first distillation stage, b) separating the resulting bottom product by distillation into a top fraction containing the oligomers of polytetrahydrofuran or of tetrahydrofuran copolymers, and polytetrahydrofuran or tetrahydrofuran copolymer, and c) condensing the oligomers of polytetrahydrofuran or of tetrahydrofuran copolymers out of the top fraction from stage b).

Abstract: The present invention relates to a process for preparing ?-bisabolol, comprising the reaction of farnesol in the presence of a ketone, of a sulfonic acid and of a further strong acid.

Abstract: The present invention relates to a process for preparing ?-bisabolol, comprising the reaction of farnesol in the presence of a ketone, of a sulfonic acid and of a further strong acid.

Abstract: The present invention provides a process for preparing mono- or diesters of polytetrahydrofuran or of tetrahydrofuran copolymers by polymerizing tetrahydrofuran in the presence of at least one telogen and/or of a comonomer over an acidic catalyst, wherein the polymerization reactor is started up using a mixture of polytetrahydrofuran, the mono- or diesters of polytetrahydrofuran and/or of the THF copolymers, tetrahydrofuran, any comonomer and at least one carboxylic acid and/or one carboxylic anhydride.

Abstract: A process for obtaining oligomers of polytetrahydrofuran or of tetrahydrofuran copolymers from a methanolic crude product which contains polytetrahydrofuran or tetrahydrofuran copolymers and is obtained in the transesterification of the mono- and/or diesters of polytetrahydrofuran or tetrahydrofuran copolymers with methanol, which comprises a) removing the majority of the methanol from the crude product in a first distillation stage, b) separating the resulting bottom product by distillation into a top fraction comprising the oligomers of polytetrahydrofuran or of tetrahydrofuran copolymers, and polytetrahydrofuran or tetrahydrofuran copolymer, c) condensing the oligomers of polytetrahydrofuran or of tetrahydrofuran copolymers out of the top fraction from stage b).

Abstract: The invention relates to a process for the continuous preparation of THF by reaction of a 1,4-butanediol-containing reaction mixture over a heteropolyacid catalyst which has not been predried, wherein the reaction mixture comprises 2-(4-hydroxybutoxy)tetrahydrofuran.

Abstract: The invention relates to a process for the continuous preparation of THF by reaction of a 1,4-butanediol-containing reaction mixture over a heteropolyacid catalyst which has not been predried, wherein the reaction mixture comprises 2-(4-hydroxybutoxy)tetrahydrofuran.

Abstract: In a process for preparing polytetrahydrofuran, tetrahydrofuran copolymers, diesters or monoesters of these polymers having a low color number, the polymers obtained by cationic polymerization of tetrahydrofuran are hydrogenated in the presence of a macroporous, supported heterogeneous catalyst comprising at least one metal of groups 7 to 10 of the Periodic Table of the Elements as active metal.

Abstract: In a process for preparing polytetrahydrofuran, tetrahydrofuran copolymers, diesters or monoesters of these polymers having a low color number, the polymers obtained by cationic polymerization of tetrahydrofuran are hydrogenated in the presence of a macroporous, supported heterogeneous catalyst comprising at least one metal of subgroups VII [sic] to X [sic] of the Periodic Table of the Elements as active metal.

Abstract: Sugar ketals are prepared by reacting a sugar with a ketone in the presence of an acid catalyst by a process in whichA. a molecular boron trifluoride compound or trifluoromethanesulfonic acid is used in an amount of only from 0.01 to 10% by weight, based on the sugar used,B. up to a 30-fold molar excess of the ketone is used andC. the water formed during the reaction is removed continuously from the reaction mixture.In a particularly advantageous embodiment of the process, the boron trifluoride is used in the form of boron trifluoride etherate and, when the reaction is complete, this compound or the trifluoromethanesulfonic acid is rendered ineffective under non-aqueous conditions, after which the ketone is evaporated off and the reaction mixture is then subjected to fractional distillation. The process is particularly important for the reaction of L-sorbose with acetone to obtain 2,3:4,6-di-O-isopropylidene-L-sorbofuranose, which is required for the synthesis of ascorbic acid.