Abstract: Process for the preparation of resorcinol monoalkyl ethers by dehydrogenizing 3-alkoxycyclohexene-(2)-ones in the liquid or gaseous phase.

Abstract: Cyclohexane-1,3-diones of the formula ##STR1## having up to 24 carbon atoms are prepared in admixture with 6-alkyl-3,4-dihydro-2-pyranones of the formula ##STR2## having up to 24 carbon atoms, in which formulae the radicals R and R' may be identical or different and represent each a hydrogen atom, an alkyl, a cycloalkyl or an aryl group each having up to 12 carbon atoms and the two radicals R' together optionally represent a --(CH.sub.2).sub.3 -group, by passing 4-oxocarboxylic acids of the formula ##STR3## having up to 24 carbon atoms and in which R and R' have the above meaning at a temperature of from 250.degree. to 500.degree. C in the gaseous phase over a dehydration catalyst and the pyranones are converted into cyclohexane-1,3-diones by passing them in the gaseous phase over a dehydration catalyst at a temperature of from 250.degree. to 500.degree. C.

Abstract: Cyclohexanediones-1,3 are prepared in a good selectivity by reacting an .alpha.,.beta.-unsaturate carboxylic acid ester with a ketone in the liquid phase in the presence of a strong base and a solvent selected from the group consisting of carboxylic acid amides, phosphoric acid amides, sulfoxides, sulfones, and glycol dialkyl ethers.

Abstract: The present invention is related to a process for the manufacture of hydroquinone by catalytic dehydrogenation of cyclohexanedione-(1,4) in the liquid phase by means of a dehydrogenation mixture composed of a solvent and a catalyst comprising a noble metal of Group VIII of the periodical system.

Abstract: Process for preparing resorcinols from .delta.-ketocarboxylic acids or their lactones in the gaseous phase at temperatures from 150.degree.14 500.degree. C by means of a dehydrogenation catalyst.