Abstract: In a process for preparing polytetrahydrofuran, polytetrahydrofuran copolymers or diesters or monoesters thereof by polymerization of tetrahydrofuran in the presence of at least one telogen and/or comonomer over acid-activated montmorillonite catalysts, the montmorillonite catalyst after acid activation has a ratio of montmorillonite structure to the sum of muscovite and kaolin structures, determined from the intensities of the reflections at 2&thgr;=5.5° for montmorillonite, 2&thgr;=9.0° for muscovite and 2&thgr;=12.5° for kaolin measured in the X-ray powder pattern, of at least 5:1.

Abstract: In a process for preparing polytetrahydrofuran, tetrahydrofuran copolymers, diesters or monoesters of these polymers having a low color number by polymerization of tetrahydrofuran in the presence of at least one telogen and/or comonomer over a heterogeneous catalyst, the polymerization is carried out in the presence of hydrogen.

Abstract: In a process for preparing carbonyl compounds of the formula ##STR1## where R.sup.1 is a hydrogen atom or an alkyl radical having from 1 to 3 carbon atoms, R.sup.2 is a hydrogen atom or a radical of the formula ##STR2## where R.sup.3 is a hydrogen atom or together with R.sup.4 is an oxygen atom, R.sup.4 is the radical OR.sup.6 or together with R.sup.3 is an oxygen atom, R.sup.5 is a hydrogen atom, an alkyl radical having from 1 to 8 carbon atoms or a cyclohexyl or cyclopentyl radical and R.sup.6 is an alkyl radical having from 1 to 4 carbon atoms, a cyclohexyl or cyclopentyl radical or a radical of the formula --CH.sub.2 --CHO or --CH.sub.2 --CH.sub.2 --O--CH.sub.2 --CHO, by gas-phase oxidation of methanol or alcohols of the formula ##STR3## where R.sup.1 and R.sup.5 are as defined above and R.sup.7 is a hydrogen atom or a radical OR.sup.8 and R.sup.8 is a hydrogen atom, an alkyl radical having from 1 to 4 carbon atoms, a cyclohexyl or cyclopentyl radical or a radical for the formula --CH.sub.2 --CH.sub.

Abstract: An alkinol or mixture of two or more thereof is hydrogenated by bringing the alkinol or the mixture of two or more thereof into contact with a hydrogen-containing gas in the presence of a catalyst comprising as active metal at least one metal of transition group VIII of the Periodic Table, either alone or together with at least one metal of transition group I or VII of the Periodic Table, applied to a support, wherein the support contains macropores.

Abstract: The present invention relates to a process for the preparation of carbonyl compounds of the formula ##STR1## in which R.sup.1 denotes a hydrogen atom or an alkyl radical containing from 1 to 3 carbon atoms, R.sup.2 denotes a hydrogen atom or a radical of the formula ##STR2## in which R.sup.3 denotes a hydrogen atom or, together with R.sup.4, an oxygen atom, R.sup.4 denotes the radical OR.sup.6 or, together with R.sup.3, an oxygen atom, R.sup.5 denotes a hydrogen atom or an alkyl radical containing from 1 to 8 carbon atoms or a cyclohexyl or cyclopentyl radical, and R.sup.6 denotes an alkyl radical containing from 1 to 4 carbon atoms, a cyclohexyl or cyclopentyl radical or a radical of the formula--CH.sub.2 --CHO or --CH.sub.2 --CH.sub.2 --O--CH.sub.2 --CHO,by gas-phase oxidation of methanol or alcohols of the formula ##STR3## in which R.sup.1 and R.sup.5 have the meanings specified above and R.sup.7 denotes a hydrogen atom or a radical OR.sup.8, and R.sup.

Abstract: A process for the preparation of butyrolactones of the formula I ##STR1## where the substituents R.sup.1 and R.sup.2 are hydrogen, alkyl or hydroxyalkyl groups, or aryl and trialkylsilyl groups, if appropriate carrying inert: substituents, is described in which an alkyne of the formula IIR.sup.1 --C.tbd.C--R.sup.2 IIwhere the substituents have the meanings indicated above, is reacted under reducing conditions at elevated pressure and elevated temperature with carbon monoxide CO and hydrogen in the presence of a transition metal catalyst or with carbon monoxide and water in the presence of a transition metal catalyst.

Abstract: A process for hydrogenating aromatic compounds in which at least one hydroxyl group is bonded to an aromatic ring comprises bringing at least one of these compounds into contact with free hydrogen in the presence of a catalyst, wherein the catalyst comprises ruthenium and, if desired, at least one metal of transition groups I, VII and VIII in an amount of from 0.01 to 30% by weight, preferably from 0.2 to 15% by weight, based on the total weight of the catalyst, applied to a support, where the support has a mean pore diameter of at least 0.1 .mu.m, preferably at least 0.5 .mu.m, and a surface area of at most 15 m.sup.2 /g, preferably at most 10 m.sup.2 /g.

Abstract: Aromatic compounds in which at least one amino group is bonded to an aromatic nucleus are catalytically hydrogenated in the liquid phase by a process in which the catalyst consists essentially of ruthenium and, optionally at least one metal of subgroup I, VII or VIII in an amount of from 0.01 to 30% by weight, based on the total weight of the catalyst, applied to a carrier which has a mean pore diameter of at least 0.1 .mu.m and a surface area of not more than 15 m.sup.2 /g.