Abstract: A process for the separation of 1,4-butanediol from mixtures obtained by the catalytic hydrogenation of maleates, fumarates, and/or succinates, which also contain tetrahydrofuran, water, C.sub.1 -C.sub.4 alcohols, succinic diesters, hydroxybutyrates, alkylhydroxyalkyl succinates, gamma-butyrolactone and butyrates, in addition to 1,4-butanediol, comprising the following steps:a) separating, in a first column having an actual number of plates of from 20 to 70 and operated at a top pressure of from 50 to 1100 mbar and preferably from 50 to 500 mbar and a top temperature of from 40.degree. to 120.degree. C., alcohol, water and tetrahydrofuran, as overhead product,b) feeding the bottom product of the first column into a second column having an actual number of plates of from 30 to 90 and withdrawing the overhead product consisting of alcohol and butyrate and obtained at a top pressure of from 45 to 250 mbar and a top temperature of from 45.degree. to 120.degree. C.

Abstract: A process is described for isolating tetrahydrofuran from mixtures containing tetrahydrofuran, 1,4-butanediol, -butyrolactone and succinic acid esters, in which the mixtures are heated to from 150.degree. to 250.degree. C. in the presence of phyllosilicates, the resultant tetrahydrofuran and water of reaction are removed from the reaction mixture by distillation, and the tetrahydrofuran is separated from the distillate.

Abstract: A process for the preparation of 1,4-butanediol by catalytically hydrogenating maleic anhydride in the presence of an alcohol, at elevated temperature and elevated pressure and with the aid of a cobalt-containing catalyst comprises partially hydrogenating the reaction mixture in a first hydrogenation step at from 100.degree. to 200.degree. C. and at from 30 to 200 bar and subsequently post-hydrogenating the product of this first hydrogenation step, without further work-up at higher temperature and pressure than in the first hydrogenation step, in a second hydrogenation step at from 200.degree. to 300.degree. C. and at from 200 to 350 bar.

Abstract: Cyclohexanol is removed from aqueous solutions containing it and aromatic sulfonic acid by extraction using as the extractant a mixture of(a) one or more liquid aliphatic, cyloaliphatic or aromatic hydrocarbons, halohydrocarbons or ethers which are inert under extraction conditions and(b) one or more phenols.

Abstract: Cyclohexanol is removed from aqueous solutions containing it and aromatic sulfonic acids by extraction with one or more cyclohexyl ethers liquid under extraction conditions and having the formula ##STR1## where R is alkyl of from 1 to 16 catbon atoms, cycloalkyl of from 5 to 8 carbon atoms, aralkyl of from 7 to 10 carbon atoms or phenyl, which may additionally have substituents which are inert under reaction conditions.

Abstract: Cyclohexanol is removed from aqueous solutions containing it and aromatic sulfonic acids, obtained by hydrating cyclohexene in aqueous solutions of aromatic sulfonic acids at elevated temperatures and subsequent removal of excess cyclohexene, by(a) feeding the aqueous solution which contains the cyclohexanol and the aromatic sulfonic acid into the upper third of a first column and from 1 to 50 parts by weight of steam per part by weight of cyclohexanol into the bottom third of the column, withdrawing at the top of the column a vapor which consists essentially of cyclohexanol, cyclohexene and water, and obtaining as a bottom product an aqueous solution of the aromatic sulfonic acid,(b) condensing the vapor which consists essentially of cyclohexanol, cyclohexene and water and(b1) obtaining a cyclohexanol-rich phase and(b2) an aqueous phase,(c) utilizing the aqueous phase (b2) for generating the steam required in stage (a) and any remainder for the hydration of cyclohexene, and(d) distilling off from the cyclohe

Abstract: Process for the preparation of 1,4-butanediol or tetrahydrofuran or both by the catalytic hydrogenation of maleic anhydride, succinic anhydride, maleic acid, succinic acid, fumaric acid, or the alkyl esters of these acids at temperatures of from 100.degree. C. to 350.degree. C. and pressures of from 50 bar to 350 bar over a catalyst containing cobalt as the active metal and one or both of the elements copper and phosphorus, if necessary in the presence of an aliphatic alcohol.

Abstract: 3-pentenoates are prepared by isomerization of 2-pentenoates to 3-pentenoates by a process in which the 2-pentenoate is treated with from 0.01 to 0.5 mole of cyclic tertiary amine having a pK.sub.a of >6 per mold of 2-pentenoate at from 50.degree. to 250.degree. C. and the 3-pentenoate is distilled off continuously.

Abstract: 3-Pentenoates are prepared by isomerization of 2-pentenoates to 3-pentenoates by a process in which the 2-pentenoate is treaated with from 0.01 to 0.5 mole of cyclic tertiary amine having a pK.sub.a of >6 per mole of 2-pentenoate at from 50.degree. to 250.degree. C. and the 3-pentenoate is distilled off continuously.