Abstract: A process for preparing 1,4-butanediol by continuous catalytic hydrogenation of 1,4-butynediol comprises reacting 1,4-butynediol with hydrogen in the liquid continuous phase in the presence of a heterogeneous hydrogenation catalyst at from 20 to 300° C., a pressure of from 1 to 200 bar and values of the liquid-side volumetric mass transfer coefficient kLa of from 0.1 s−1 to 1 s−1 a) using a catalyst suspended in the reaction medium, where if a packed bubble column is employed this is operated in the upflow mode and at a ratio of gas leaving the reaction vessel to gas fed to the reaction vessel of from 0.99:1 to 0.4:1, or b) passing the liquid and gas in cocurrent in an upward direction through a fixed-bed reactor operated in the gas-circulation mode while maintaining a ratio of the gas fed to the reaction vessel to gas leaving the reaction vessel of from 0.99:1 to 0.4:1.

Abstract: A process for preparing tetrahydrofuran, which comprises reacting 1,4-butenediol diethers of the formulae I and/or II RO—CH2—CH═CH—CH2—OR  I RO—CH2—CH2═CH—CH2—OR  II, where the R radicals can be identical or different and are C1-C15-alkyl or cycloalkyl radicals, C6-C12-aryl radicals or C7-C15-aralkyl radicals, with water and hydrogen at from 20 to 300° C. under from 1 to 300 bar in the presence of catalysts or catalyst combinations which comprise components which are both capable of hydrogenation and have acidic or basic centers and a novel process for preparing 1,4-butanediol diethers of the formula I by metathesis are described.

Abstract: In a process for preparing aliphatic alcohols by hydrogenating aliphatic carboxylic acids or anhydrides or esters thereof or lactones in the presence of a catalyst comprising Pt and Re, in the form of the metal or an oxide in each case, the catalyst further comprises at least one further element from the groups 5 to 12 and 14 and the lanthanides of the Periodic Table of the Elements in the form of the metal or an oxide.

Abstract: A process for hydrogenating polyenes, especially 1,5,9-cyclododecatriene, to the corresponding monoenes, especially cyclododecene, using homogeneous ruthenium catalysts comprises hydrogenating in the presence of a carboxylic acid, advantageously a C1-C20 monocarboxylic acid, a C2-C6 dicarboxylic acid, cyclohexylcarboxylic acid, benzoic acid, terephthalic acid, phthalic acid or phenylacetic acid, especially acetic acid, propionic acid, succinic acid or adipic acid or a C12-C20 fatty acid. The homogeneous ruthenium catalyst is advantageously generated in situ prior to the hydrogenation. The in situ generation is carried out in the additional presence of CO or formaldehyde and the hydrogenation in the additional presence of triphenylphosphine.

Abstract: A process for preparing tetrahydrofuran, which comprises reacting 1,4-butenediol diethers of the formulae I and/or II RO—CH2—CH═CH—CH2—OR  I RO—CH2—CH2═CH—CH2—OR  II, where the R radicals can be identical or different and are C1-C15-alkyl or cycloalkyl radicals, C6-C12-aryl radicals or C7-C15-aralkyl radicals, with water and hydrogen at from 20 to 300° C. under from 1 to 300 bar in the presence of catalysts or catalyst combinations which comprise components which are both capable of hydrogenation and have acidic or basic centers and a novel process for preparing 1,4-butanediol diethers of the formula I by metathesis are described.

Abstract: A process for preparing tetrahydrofuran, which comprises reacting 1,4-butenediol diethers of the formulae I and/or IIRO--CH.sub.2 --CH.dbd.CH--CH.sub.2 --OR IRO--CH.sub.2 --CH.sub.2 .dbd.CH--CH.sub.2 --OR II,where the R radicals can be identical or different and are C.sub.1 -C.sub.15 -alkyl or cycloalkyl radicals, C.sub.6 -C.sub.12 -aryl radicals or C.sub.7 -C.sub.15 -aralkyl radicals, with water and hydrogen at from 20 to 300.degree. C. under from 1 to 300 bar in the presence of catalysts or catalyst combinations which comprise components which are both capable of hydrogenation and have acidic or basic centers and a novel process for preparing 1,4-butanediol diethers of the formula I by metathesis are described.The invention furthermore relates to the separate preparation of 1,4-butanediol monoethers of the formula IIIHO--CH.sub.2 --CH.sub.2 --CH.sub.2 --CH.sub.

Abstract: A process for preparing cyclopentyl formates of the formula (II) ##STR1## by reacting cyclopentenes of the formula (I) ##STR2## where R.sup.1, R.sup.2 and R.sup.3, independently of one another, are hydrogen atoms or C.sub.1-8 -alkyl,with formic acid in the presence of an acid catalyst.

Abstract: 1,6-Hexanediol is prepared from a carboxylic acid mixture comprising adipic acid, 6-hydroxycaproic acid and small amounts of 1,4-cyclohexanediols which is obtained as a by-product in the oxidation of cyclohexane to cyclohexanone/cyclohexanol by water extraction of the reaction mixture, by esterification of the acids and hydrogenation whereina) the monocarboxylic and dicarboxylic acids present in the aqueous dicarboxylic acid mixture are reacted with a low molecular weight alcohol to give the corresponding carboxylic esters,b) the resulting esterification mixture is freed of excess alcohol and low boilers in a first distillation stage,c) the bottoms are fractionated in a second distillation stage to give an ester fraction essentially free of 1,4-cyclohexanediols and a fraction comprising at least the major part of the 1,4-cyclohexanediols,d) the ester fraction essentially free of 1,4-cyclohexanediols is catalytically hydrogenated ande) in a pure distillation stage, 1,6-hexanediol is isolated from the hydrogena

Abstract: 1,6-hexanediol and .epsilon.-caprolactone are prepared from a carboxylic acid mixture comprising adipic acid, 6-hydroxycaproic acid and small amounts of 1,4-cyclohexanediols which is obtained as a by-product in the oxidation of cyclohexane to cyclohexanone/cyclohexanol using oxygen or oxygen-containing gases by water extraction of the reaction mixture, by esterifying and hydrogenating a substream to give hexanediol and cyclizing 6-hydroxycaproic esters to give caprolactone.

Abstract: In a process for the catalytic hydrogenation of 2,5- and 2,3-dihydrofuran with hydrogen to give tetrahydrofuran, use is made of a catalyst in which a metal or a plurality of metals have been deposited by vapor deposition or sputtering on a metal wire mesh or a metal foil as support.

Abstract: 1,6-Hexanediol is prepared bya) Reacting epoxybutadiene in the presence of a metathesis catalyst with elimination of ethene to give bisepoxyhexatrienes of the formulae Ia and Ib ##STR1## and b) hydrogenating these bisepoxyhexatrienes with hydrogen to give 1,6-hexanediol.

Abstract: Described is a method of producing 1,4-butanediol, the method calling for 2,3-dihydrofuran to be decomposed in a single stage over a hydrogenation catalyst in the presence of water and hydrogen at a temperature of 20 to 300.degree. C. and a pressure of 1 to 300 bar and in neutral or acid conditions.

Abstract: 1,4-butanediol and THF are prepared from furan by a process which comprises converting furan in the presence of water and hydrogen but in the absence of a water-soluble acid in a single stage over a hydrogenation catalyst, the hydrogenation catalyst containing at least one element of subgroup I, V, VI, VII or VIII in the form of a compound or in elemental form and the restriction that the catalyst does not contain nickel alone being applicable.

Abstract: Impurities are separated from aqueous solutions of 1,6-hexanediol or 1,6-hexanediol precursors, such as adipic and 6-hydroxycaproic acid, by a process which comprises adding at least one carboxylic acid to a solution (a) of 1,6-hexanediol and subjecting this solution (a) or a solution (b) containing carboxylic acid(s) as precursor(s) of 1,6-hexanediol to a heat treatment at temperatures above room temperature in the absence of hydrogen.

Abstract: A process for the preparation of n-butyraldehyde and/or n-butanol, whereina) 1,3-butadiene is caused to react with an alcohol of the formula IROH I,to form a mixture of adducts of the formulas II ##STR1## and III ##STR2## b) the adduct III is isomerized to the adduct II, c) the adduct II is isomerized in the presence of a homogeneous or heterogeneous transition metal element catalyst to form the enol ether of the formula IV ##STR3## and d) n-butyraldehyde and/or n-butanol is/are produced from this ether IV by the reaction thereof with hydrogen and water or water only in the presence of a homogeneous or heterogeneous catalyst.

Abstract: A process for the preparation of .gamma.-butyrolactone, in which 2,5-dihydrofuran or 2,3-dihydrofuran or a mixture of these two dihydrofurans is caused to react in the gas phase in the presence of water and in the presence or absence of additional hydrogen at elevated temperature over a hydrogenating catalyst.

Abstract: A process for the preparation of polyoxyalkylene glycols or polyoxyalkylene glycol copolymers from polyoxyalkylene glycol formates or the formates of polyoxyalkylene glycol copolymers comprises reacting the formates of polyoxyalkylene glycols or of polyoxyalkylene glycol copolymers in the liquid phase in the presence of a heterogeneous catalyst which contains, as catalytically active component, rhenium and/or at least one element from sub-group VIII of the Periodic Table of the Elements.

Abstract: A process for the preparation of cycloalkanols by the hydrolysis of cycloalkyl C.sub.1 -C.sub.4 fatty acid esters, which comprises the following steps:a) reaction of cycloalkyl C.sub.1 -C.sub.4 fatty acid esters with water at a temperature of from 30.degree. to 250.degree. in the liquid phase yielding a reaction mixture consisting of cycloalkyl C.sub.1 -C.sub.4 fatty acid esters, cycloalkanol, C.sub.1 -C.sub.4 fatty acids, and water.b) separation of the reaction mixture obtained in stage a) at a temperature of from 0.degree. to 200.degree. C. into a top phase consisting substantially of cycloalkanol and cycloalkyl C.sub.1 -C.sub.4 fatty acid esters and a bottom phase consisting substantially of water and C.sub.1 -C.sub.4 fatty acids.c) separation of cycloalkanol from the top phase obtained in stage b) by distillation and recycling unconverted cycloalkyl C.sub.1 -C.sub.4 fatty acid esters to stage a).

Abstract: A process for preparing five-membered nitrogen heterocycles of the general formula I ##STR1## where R.sup.1, R.sup.2, R.sup.3, R.sup.4, R.sup.5, R.sup.6, R.sup.7, R.sup.8 are hydrogen,R.sup.1 is C.sub.1 -C.sub.10 -alkyl, C.sub.1 -C.sub.10 -hydroxyalkyl, C.sub.1 -C.sub.10 -aminoalkyl, aryl, C.sub.7 -C.sub.10 -aralkyl and C.sub.7 -C.sub.10 -alkylaryl,R.sup.5 and R.sup.6 are C.sub.1 -C.sub.8 -alkyl,R.sup.2 and R.sup.3 together are oxygen with the proviso that R.sup.8 is hydrogen,R.sup.3 and R.sup.4 and/or R.sup.7 and R.sup.8 or R.sup.4 and R.sup.7 together are a bond,comprises reacting vinyloxiranes of the general formula II ##STR2## where R.sup.5 and R.sup.6 have the abovementioned meanings, with ammonia or primary amines of the general formula IIIR.sup.1 --NH.sub.2 (III),where R.sup.1 has the abovementioned meanings, in the presence of a compound of an element of Group VIIIb or Ib of the Periodic Table, with or without the addition of a Lewis acid, at from 20.degree. to 200.degree. C.

Abstract: A process for preparing 5-membered ring heterocycles of the general formula I ##STR1## where R.sup.1 is methyl or hydroxyethyl,R.sup.2,R.sup.3,R.sup.4,R.sup.5 and R.sup.6 are hydrogen, C.sub.1 - to C.sub.12 -alkyl, C.sub.2 - to C.sub.12 -alkenyl, aryl, C.sub.3 - to C.sub.8 -cycloalkyl, C.sub.1 - to C.sub.12 -alkoxy, halogen, C.sub.2 - to C.sub.20 -alkoxycarbonylalkyl, C.sub.2 - to C.sub.20 -alkylcarbonyloxy, formyl, C.sub.2 - to C.sub.20 -formylalkyl, benzoyl or --CH(OR.sup.3)(OR.sup.5), or R.sup.3 and R.sup.5 together are a C.sub.2 - to C.sub.7 -alkylene chain which is unsubstituted or monosubstituted to pentasubstituted by R.sup.4 or a .dbd.CH--CH.dbd.CH--CH.dbd. unit which is unsubstituted or monosubstituted to tetrasubstituted by R.sup.4,X is oxygen or N--R.sup.4by reacting 5-membered ring heterocycles of the general formula II ##STR2## where R.sup.2, R.sup.3, R.sup.4, R.sup.5, R.sup.6 and X have the abovementioned meanings and Y is hydrogen, acetyl or C.sub.2 - to C.sub.