Abstract: A process for the preparation of a 5-vinylpyrrolidone of the formula ##STR1## wherein each of R.sup.1 and R.sup.2 is hydrogen or alkyl and R.sup.3 is preferably hydrogen but may further represent alkyl, cycloalkyl, aryl, alkylaryl, arylalkyl or a 5- to 6-membered aromatic or non-aromatic heterocyclic group containing 1 to 3 nitrogen atoms and/or an oxygen or sulfur atom, the process being carried out in two steps, first to react a 3-formylpropionic acid ester of the formula ##STR2## where each of R.sup.1 and R.sup.2 is hydrogen or C.sub.1 -C.sub.8 -alkyl, and R.sup.4 is hydrogen, alkyl, cycloalkyl, aryl, alkylaryl or arylalkyl, with a vinylymagnesium halide of the formulaCH.sub.2 .dbd.CH--Mg--X V,where X is chlorine, bromine or iodine, at a temperature of from -30.degree. to 100.degree. C., under a pressure from 0.001 to 10 bar and in a molar ratio of V:IV of from 0.3:1 to 3:1 to obtain as an intermediate product a gamma-vinylbutyrolactone of the formula ##STR3## where R.sup.1 and R.sup.

Abstract: Crude capronitrile is purified by hydrogenation, subsequent treatment in an acidic medium and subsequent distillation in an alkaline medium, by a process in which(a) 6-aminocapronitrile is converted into crude caprolactam by reaction with water,(b) high boilers and low boilers are separated off from the crude caprolactam from step (a),(c) the crude caprolactam from step (b) is treated with hydrogen at from 50.degree. to 150.degree. C. and from 1.5 to 250 bar in the presence of a hydrogenation catalyst and, if desired, of a solvent to give a mixture A,(d1) mixture A in a solvent is passed, at from 30.degree. to 80.degree. C. and from 1 to 5 bar, over an ion exchanger containing terminal acid groups to give a mixture B1, or(d2) mixture A is distilled in the presence of sulfuric acid, any solvent present being removed before the addition of the sulfuric acid, to give a mixture B2, and(e) mixture B1 or mixture B2 is distilled in the presence of a base to give pure caprolactam.

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 the preparation of 3-(2'-acyloxyethyl)-dihydro-2(3H)furanones of the general formula I ##STR1## in which R.sup.1 denotes C.sub.1 -C.sub.12 alkyl, C.sub.5 -C.sub.8 cycloalkyl, aryl, C.sub.7 -C.sub.12 aralkyl, or C.sub.7 -C.sub.12 alkylaryl, in which a 3-(2'-oxyethyl)-dihydro-2(3H)furanone of the general formula II ##STR2## in which R.sup.2 denotes C.sub.1 -C.sub.12 alkyl, C.sub.5 -C.sub.8 cycloalkyl, aryl, C.sub.7 -C.sub.12 aralkyl, or C.sub.7 -C.sub.12 alkylaryl is caused to react with a carboxylic acid, a carboxylic anhydride, and/or an acyl halide in the presence of an acid catalyst at temperatures of from 50.degree. to 250.degree. C. and pressures of from 0.1 to 100 bar.

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.

Abstract: A process for the preparation of a .alpha.,.omega.-dicarboxylic acid diester of the general formula I ##STR1## in which R.sup.1, R.sup.2, R.sup.3, R.sup.4, R.sup.5 denotes hydrogen, C.sub.1 -C.sub.20 alkyl, C.sub.2 -C.sub.20 alkenyl, C.sub.2 -C.sub.20 alkynyl, C.sub.2 -C.sub.20 alkoxycarbonyl, nitro, C.sub.2 -C.sub.20 alkoxy and/or cyano andn is an integer from 1 to 12,wherein cycloalkanones of the general formula II ##STR2## in which R.sup.1, R.sup.2, R.sup.3, R.sup.4, R.sup.5 and n have the aforementioned meanings, are caused to react with dimethylcarbonate in the presence of a nitrogenous base of the general formula III ##STR3## in which R.sup.6, R.sup.7, R.sup.8 denote hydrogen, C.sub.1 -C.sub.20 alkyl, C.sub.3 -C.sub.8 cycloalkyl or C.sub.7 -C.sub.20 aralkyl or R.sup.6 and R.sup.7 together form a C.sub.2 -C.sub.7 alkylene chain optionally mono- to penta-substituted by R.sup.1,at temperatures ranging from 50.degree. to 300.degree. C.

Abstract: A process for the preparation of 2,6-dimethylmorpholine from N-(2-hydroxypropyl)-2,6-dimethylmorpholine, in which N-(2-hydroxypropyl)-2,6-dimethylmorpholine, in whicha) N-(2-hydroxypropyl)-2,6-dimethylmorpholine is caused to react in the presence of a catalyst containing an element listed in Groups Ib, IIb, and/or VIIIb of the Periodic Table at temperatures ranging from 150.degree. to 600.degree. C. and is then caused to react with water at temperatures ranging from 30.degree. to 300.degree. C. orb) N-(2-hydroxypropyl)-2,6-dimethylmorpholine is caused to react in the presence of an acid catalyst at temperatures ranging from 100.degree. to 400.degree. C. followed by acid hydrolysis with water at temperatures ranging from 30.degree. to 300.degree. C.

Abstract: The preparation of N-substituted 2-pyrrolidones (I) by the reaction of maleic acid, fumaric acid, or succinic acid or functional derivatives of these acids (compounds II) with a primary amine (III) or by the reaction of amides or imides derived from II and III under hydrogenating conditions in a synthesis stage followed by isolation, by distillation, of I and other volatile components from the resulting reaction mixture, in which the residues present following distillation are subjected to further hydrogenation treatment and the compound (I) thus formed is isolated by distillation.

Abstract: Polyoxyalkylene glycols are prepared by a process in which tetrahydrofuran is polymerized with a total of not more than 95 mol %, based on the amount of tetrahydrofuran used, of one or more comonomers from the group consisting of the cyclic ethers and acetals in the absence of water and in the presence of a monohydric alcohol or of a monocarboxylic acid with the aid of an anhydrous heteropoly acid catalyst, and the polyoxyalkylene glycol is liberated from the resulting polyoxyalkylene glycol monoethers or polyoxyalkylene glycol monoesters by cleavage of the monoether or monoester bond.

Abstract: Polyoxyalkylene glycol monoethers of monohydric alcohols are prepared by a process in which tetrahydrofuran or a mixture of tetrahydrofuran with a total of not more than 95 mol %, based on the amount of tetrahydrofuran used, of one or more comonomers from the group consisting of the cyclic ethers and acetals is polymerised in the absence of water and in the presence of a monohydric alcohol and of an anhydrous heteropoly acid catalyst.

Abstract: A process for purifying esters of tetrahydropyran-4-carboxylic acid of the formula I ##STR1## where R.sup.1 to R.sup.3 are each C.sub.1 -C.sub.4 -alkyl, and R.sup.2 and R.sup.3 are each additionally hydrogen, from mixtures produced in the reaction of butyrolactones of the formula II ##STR2## where R.sup.2 and R.sup.3 have the abovementioned meanings, and R.sup.4 is hydrogen, alkyl of 1-6 carbons or acyl of the formula --CO--R.sup.2, with alcohols of the formula R.sup.1 OH in the presence of oxide catalysts, by distillation, which entailsa) removing overhead, in a first column with 5-25 theoretical plates with a distillate pressure of 700-1100 mbar and a distillate temperature of 50.degree.-80.degree. C.

Abstract: A process for preparing monocarboxylic esters of the general formula I ##STR1## where R.sup.1 and R.sup.2 are each hydrogen, C.sub.1 -C.sub.12 -alkyl, C.sub.3 -C.sub.8 -cyclo-alkyl acyl, aryl or C.sub.7 -C.sub.20 -aralkyl or together --(CH.sub.2).sub.n --X--(CH.sub.2).sub.m --,X is methylene, oxygen, sulfur, NH or NR.sup.3,R.sup.3 is C.sub.1 -C.sub.12 -alkyl, andn and m are each from 0 to 8, comprises reacting geminal dicarboxylic esters of the general formula II ##STR2## where R.sup.1 to R.sup.3 are each as defined above, at from 150.degree. to 400.degree. C. in the presence of catalysts.

Abstract: The average molecular weight of polyoxyalkylene glycols and polyoxyalkylene glycol derivatives is adjusted in the heteropolyacid-catalyzed polymerization of cyclic ethers and/or acetals with ring cleavage in the presence of proton donors by a process in which the amount of the relevant proton donor present in the reaction system is regulated in the course of the reaction by the measurement of the electrical conductivity.

Abstract: A process for the preparation of N-(2-hydroxypropyl)-2,6-dimethylmorpholine, wherein tris-(2-hydroxypropyl)amine is cyclizeda) in the presence of acid catalysts orb) in the presence of hydrogenation catalysts.

Abstract: A process for the preparation of propane-1,2,3-tricarboxylic acid, tetrahydrofurfurylacetic acid and the C.sub.1 - to C.sub.20 -alkyl or C.sub.7 - to C.sub.12 -aralkyl esters thereof, propane-1,2,3-trimethanol, 3-methyltetrahydrofuran, 3-(2'-hydroxyethyl)tetrahydrofuran, 4-hydroxymethyltetrahydropyran, 2-methyl-.gamma.-butyrolactone and/or 3-methyl-.gamma.-butyrolactone, comprises reacting citric acid or the C.sub.1 - to C.sub.20 -alkyl or C.sub.7 - to C.sub.12 -aralkyl esters thereof on hydrogenation catalysts in non-aqueous solvents at from 50.degree. to 400.degree. C. and at from 1 to 400 bar.

Abstract: A process for preparing 4-hydroxymethyltetrahydropyran comprises reacting tetrahydrofurans of the general formula I ##STR1## where R.sup.1 is hydrogen, C.sub.1 - to C.sub.6 -alkyl or --CO--R.sup.2, andR.sup.2 is hydrogen or C.sub.1 - to C.sub.6 -alkyl,at from 0.degree. to 400.degree. C. and from 0.001 to 400 bar in the presence of acidic catalysts.

Abstract: A process for the continuous production of cyclohexene from a cyclohexyl ester of a carboxylic acid having 1 or 2 carbon atoms, which comprises the following steps:a) heating a cyclohexyl ester of a carboxylic acid having 1 or 2 carbon atoms in the presence of an acid catalyst with the formation of cyclohexene and a carboxylic acid having 1 or 2 carbon atoms;b) removing, by distillation, cyclohexene and carboxylic acid having 1 or 2 carbon atoms from the reaction mixture from stage a) at the same rate as they are formed;c) adding a cyclohexyl ester of a carboxylic acid having 1 or 2 carbon atoms to stage a) at the rate cyclohexene and carboxylic acid are distilled off; andd) separating the mixture comprising cyclohexene and carboxylic acid having 1 or 2 carbon atoms coming from stage b).

Abstract: Abstract of the Disclosure: Products of the reduction of 4-hydroxybutyric acid derivatives of the formula IIa ##STR1## where one of A and B is methylene and the other is cyclopropylidene, or of C.sub.1 --C.sub.4 --alkyl esters (IIb) or lactones (IIc) of these acids IIa, are prepared by hydrogenating the compounds IIa or IIb or IIc catalytically using hydrogen in the presence of a heterogeneous hydrogenation catalyst, giving novel compounds which can be used to prepare polymers.

Abstract: A process for the preparation of aldehydes of the general formula I ##STR1## in which R.sup.1, R.sup.2 denote hydrogen, C.sub.1 -C.sub.12 alkyl, C.sub.3 -C.sub.8 cycloalkyl, acyl, aryl, or C.sub.7 -C.sub.20 aralkyl or together stand for --(CH.sub.2).sub.n --X--(CH.sub.2).sub.m --,X denotes methylene, oxygen, sulfur, NH or NR.sub.3 andn, m stand for an integer from 0 bis 8,wherein a geminal formyl ester of the general formula II ##STR2## in which R.sup.1 and R.sup.2 have the aforementioned meanings and R.sup.3 denotes C.sub.1 -C.sub.12 alkyl, is caused to react in the presence of an acid catalyst at temperatures ranging from 150.degree. to 400.degree. C.