Abstract: are prepared by single-stage reaction of alkoxydihydropyrans of the formula (II) with water and hydrogen in the presence of a catalyst comprising oxides of nickel, zirconium and copper. In the formulae (I) and (II), R, R′, R″, R′″ can be identical or different and are each hydrogen or a linear or branched saturated hydrocarbon radical having from 1 to 20 carbon atoms in which the hydrocarbon chain may contain O, S and N as heteroatoms and which may be monosubstituted or polysubstituted by hydroxy, thiol or amino groups or halogens.

Abstract: The present invention relates to a process for preparing propene by metathesis of olefins.

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 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: Preparation of 5-cyanovalerates (I) by the carbonylation of a 1-cyanobutene with carbon monoxide and an alkanol (II) corresponding to the ester radical at an elevated temperature and under superatmospheric pressure in the presence of a cobalt catalyst as well as in the presence of an activating solvent, in which the activating solvent used is an effective amount of a urea of the formula IIIcR.sub.2 N--CO--NR.sub.2 (IIIc)where R is, C.sub.1 -C.sub.6 -alkyl, C.sub.5 -C.sub.7 -cycloalkyl or where 2R groups together form 5-membered to 7-membered rings. The end products I serve as intermediates, chiefly for the preparation of .epsilon.-caprolactam.

Abstract: Preparation of 5-cyanovalerates (I) by the carbonylation of a 1-cyanobutene with carbon monoxide and an alkanol (II) corresponding to the ester radical at an elevated temperature and under superatmospheric pressure in the presence of a cobalt catalyst as well as in the presence of an activating solvent, in which the activating solvent used is an effective amount of a carbonic diester, a carbamate, or a urea of the general formula IIIa, IIIb, or IIIcR--O--CO--O--R (IIIa)R.sub.2 N--CO--O--R (IIIb)R.sub.2 N--CO--NR.sub.2 (IIIc)or a mixture of these compounds (R's same or different, C.sub.1 -C.sub.6 alkyl, C.sub.5 -C.sub.7 cycloalkyl groups or together form 5-membered to 7-membered rings).The end products I serve as intermediates, chiefly for the preparation of .epsilon.-caprolactam.

Abstract: A process for the preparation of formic acid by the reaction of carbon monoxide with water at temperatures of from 100.degree. to 250.degree. C. and absolute from 100 to 350 bar, in which tertiary amines of the general formula I ##STR1## in which R.sup.1, R.sup.2, R.sup.3 individually denote C.sub.1 -C.sub.14 alkyl, C.sub.3 -C.sub.8 cycloalkyl, aryl, and C.sub.7 -C.sub.16 aralkyl or together denote a 1,4-alkylene group or 1,5-alkylene group optionally mono- to tetra-substituted by C.sub.1 -C.sub.4 alkyl, provided that the total number of carbon atoms in R.sup.1, R.sup.2, and R.sup.3 is from 3 to 40,are added to the reaction mixture.