Abstract: Distillative separation of liquid mixtures of one or more water-insoluble substances which have boiling points higher than that of water and one or more substances which have boiling points lower than that of water or which form azeotropes having boiling points lower than that of water, wherein the mixture to be distilled is mixed with a quantity of water such that the boiling point of the water under the pressure applied limits the bottom temperature of the mixture of substances to be separated.

Abstract: Chroman derivatives of the general formula I ##STR1## where R.sup.1, R.sup.2, R.sup.3 and R.sup.4 are each H or C.sub.1 -C.sub.4 -alkyl, R.sup.5 is C.sub.10 -C.sub.30 -alkyl or C.sub.10 -C.sub.30 -alkenyl, X and Y are each O, NH or S, m is 0, 1, 2 or 3 and n and r are each 0 or 1, the preparation of compounds I by various methods known per se, and the use of the compounds as stabilizers for organic materials.

Abstract: The invention relates to ethoxylates of diacetylene dialcohols as well as the use of these compounds as surfactants.

Abstract: Olefinically unsaturated alcohols (I) are prepared by selective hydrogenation of the corresponding carbonyl compounds (II) in the liquid phase with hydrogen, using an Ru, Rh, Os, Ir or Pt catalyst and carrying out the hydrogenation in the presence of from 5 to 40% by weight, based on (II), of a tertiary amine.The process is of particular importance for the selective hydrogenation of .alpha.,.beta.-unsaturated carbonyl compounds (IIa) and amongst these specifically for the hydrogenation of citral to geraniol and nerol.The preferred amine is trimethylamine.

Abstract: 4-(2,5-Dihydroxyphen-1-yl)-crotonic acid and its derivative (I) ##STR1## where R.sup.1, R.sup.2, R.sup.3 and R.sup.4 are each H or C.sub.1 -C.sub.8 -alkyl, R.sup.5 is H, C.sub.1 -C.sub.30 -alkyl or C.sub.2 -C.sub.30 -alkenyl, and R' is H or an organic radical which can be split off hydrogenolytically, and a process for the preparation of the compounds I, wherein a hydroquinone II ##STR2## is reacted, in the presence of from 0.1 to 2 moles of a Lewis acid per mole of II, with(a) a vinylglycolic acid derivative IIIa ##STR3## or (b) a crotonic acid derivative IIIb ##STR4## where X is halogen, hydroxyl or C.sub.1 -C.sub.4 -alkoxy or acyloxy.

Abstract: 2-Hydroxyalkylchromans (I) ##STR1## where R.sup.1, R.sup.2, R.sup.3 and R.sup.4 are each H or C.sub.1 -C.sub.8 -alkyl, R' is H or an organic radical which can be split off hydrolytically or hydrogenolytically as R'-OH or R'-COOH, and m is 1, 2 or 3, are prepared by reacting a hydroquinone II ##STR2## (a) with an alkenediol IIIa ##STR3## or (b) with an alkenediol IIIb ##STR4## or (c) with an alkenediol IIIc ##STR5## where R.sup.4' is a radical which during the condensation with II is converted to the radical R.sup.4,at from -50.degree. C. to 120.degree. C., in an inert solvent, in the presence of from 10 to 300 mole %, based on II, of a Lewis acid or of an adduct of a Lewis acid with a Lewis base which has a lower basicity than compound II.

Abstract: Olefinically unsaturated carbonyl compounds R.sup.1 --CHR.sup.2 --CHR.sup.3 --C(R.sup.4)O (I) and alcohols R.sup.1 --CHR.sup.2 --CHR.sup.3 --CH(R.sup.4)--OH (II) (where R.sup.1 is an olefinically unsaturated organic radical, and R.sup.2, R.sup.3 and R.sup.4 are H or C.sub.1 -C.sub.4 -alkyl) are prepared by hydrogenating the carbonyl compounds R.sup.1 --CR.sup.2 .dbd.CR.sup.3 --C(R.sup.4)O (III) in the liquid phase with hydrogen, using a catalyst system comprising, firstly, Pd and, secondly, Ru, Rh, Os, Ir or Pt, in the presence of from 5 to 40% by weight, based on (III), of a tertiary amine, under a hydrogen pressure of from 1 to 20 bar is predominantly (I) is to be obtained and from 20 to 150 bar if predominantly (II) is to be obtained.The process is of particular importance for the hydrogenation of citral (IIIa) to give citronellal (Ia) or citronellol (IIa), the preferred amine being trimethylamine.

Abstract: An improved process for the preparation of higher unsaturated ketones, such as geranylacetone and farnesylacetone, by reacting a .beta.,.gamma.-unsaturated alcohol and an alkyl acetoacetate at an elevated temperature in the presence of an organic aluminum compound, with elimination, and removal, of the alcohol derived from the alkyl acetoacetate in a reactor system carrying a fractionating column. The improvement in the purity, yield, and especially space-time yield of the product is achieved by starting from an alcohol having a higher boiling point than that of the alkyl acetoacetate used, carrying out the reaction in the presence of a small amount of an inert liquid which has a boiling point between that of the alkyl acetoacetate and the alcohol to be eliminated therefrom, and ensuring that the temperature at the bottom of the fractionating column is only slightly higher than the boiling point of the added liquid, under the prevailing pressure.

Abstract: In a process for the preparation of a carboxylic acid ester of .beta.-formyl-crotyl alcohol by rearrangement of the corresponding carboxylic acid ester of 2-formyl-2-hydroxy-but-3-ene or of an acetal or acylate thereof in the presence of copper or a copper compound, followed, where relevant, by hydrolytic cleavage of the acetal or acylate, more especially in the preparation of 4,4-dimethoxy-3-methyl-crotyl acetate, the yield is improved by carrying out the rearrangement in the presence of copper (I) chloride as the catalyst and ensuring that low-boiling by-products formed during the rearrangement are removed.The products are of great importance as starting materials for an industrial synthesis of vitamin A and its derivatives.

Abstract: Citral (I) ##STR1## is prepared by heating an acetal (IIa) or (IIb) ##STR2## in the presence of an acid catalyst while continuously distilling from the reaction mixture the 3-methylbut-2-en-1-ol (III, prenol) eliminated during the reaction.

Abstract: Saturated aliphatic, cycloaliphatic and araliphatic aldehydes are prepared by selective hydrogenation of the corresponding olefinically unsaturated aldehydes with hydrogen in the liquid phase over a palladium-containing catalyst, using a catalyst system in which the active constituents are from 2 to 90% by weight of palladium and from 10 to 98% by weight of an oxide or a salt of a rare earth metal or of a mixture of different oxides and/or salts of this type.

Abstract: Aliphatic carbonyl compounds are prepared by an aldol condensation of carbonyl compounds R.sup.1 --CH.sub.2 --CO--R.sup.2 (I; R.sup.1 and R.sup.2 =H or C.sub.1 -C.sub.8 -alkyl) in the presence of hydrogen and of a catalyst which has both condensing and hydrogenating properties, by using a catalyst system wherein the active components are from 1 to 90 percent by weight of a noble metal of group VIII of the periodic table and from 10 to 99 percent by weight of an oxide or salt of a rare earth metal, or of a mixture of different oxides and/or salts of rare earth metals.

Abstract: Chromane derivatives (I) ##STR1## where R.sup.1, R.sup.2 and R.sup.3 are H or C.sub.1 -C.sub.8 -alkyl, R.sup.4 is H, C.sub.1 -C.sub.8 -alkyl or C.sub.1 -C.sub.8 -acyl and R.sup.5 is C.sub.1 -C.sub.8 -alkyl are prepared by reacting a hydroquinone (II) ##STR2## with a Lewis acid or a Lewis acid derivative having the same action, and with a nitrile CH.sub.2 .dbd.CH--C(R.sup.5)(OR.sup.6)CN (III), where R.sup.6 is H, C.sub.1 -C.sub.4 -acyl or C.sub.1 -C.sub.4 -alkyl, or with a compound from which III is formed in situ, in the presence of an inert solvent.

Abstract: Carbonyl compounds R.sup.1 --CHR.sup.2 --CHR.sup.3 --CR.sup.4 O (I, R.sup.1 =H or an organic radical; R.sup.2 -R.sup.4 =H or C.sub.1 -C.sub.4 -alkyl) are prepared by selective hydrogenation of the .alpha.,.beta.-unsaturated carbonyl compounds R.sup.1 --CR.sup.2 =CR.sup.3 --CR.sup.4 O (II) in the liquid phase by means of hydrogen in the presence of a palladium catalyst and of from 15 to 50% by weight, based on (II), of a tertiary amine.

Abstract: A process for the preparation of an indolenine of the formula ##STR1## where R, X and Y are conventional substituents, by thermal rearrangement of a compound of the formula ##STR2## to give a compound of the formula ##STR3## and cyclization of this compound in the presence of an acid catalyst.

Abstract: A process for the preparation of an indolenine of the general formula I ##STR1## where R, R.sup.1 and R.sup.2 are aliphatic radicals and R.sup.1 and R.sup.2 may also be linked and the ring A may be additionally substituted, wherein a compound of the formula II ##STR2## is heated in the presence of a Lewis acid and of a halide. The products are valuable starting compounds for the preparation of dyes.

Abstract: Aldehydes or ketones of not less than 4 or 5 carbon atoms, respectively, are manufactured in a one stage process in the liquid phase by subjecting aldehydes and/or ketones of not less than 2 or 3 carbon atoms, respectively, to an aldol condensation and hydrogenating the resulting olefinically unsaturated aldehyde, the catalyst used for the aldol condensation and hydrogenation containing nickel or cobalt or their mixtures, zinc oxide and at least one of the elements iron, arsenic, antimony, bismuth, gallium, indium, thallium, germanium, tin, lead, cadmium and mercury or compounds of the said elements.

Abstract: Aldehydes or ketones of not less than 4 or 5 carbon atoms, respectively, are manufactured in a one stage process in the liquid phase by subjecting aldehydes and/or ketones of not less than 2 or 3 carbon atoms, respectively, to an aldol condensation and hydrogenating the resulting olefinically unsaturated aldehyde, the catalyst used for the aldol condensation and hydrogenation containing a mixture of nickel and cobalt, zinc oxide and at least one of the elements iron, arsenic, antimony, bismuth, gallium, indium, thallium, germanium, tin, lead, cadmium and mercury or compounds of the said elements.

Abstract: An improved process for the manufacture of 2-methyl-2-hepten-6-one by reacting an alkyl acetoacetate with 2-methyl-3-buten-2-ol in the presence of an organic aluminum compound such as aluminum trialcoholate, aluminum triacetoacetate, aluminum alkylacetoacetate or aluminum triaryloxylate. 2-Methyl-2-hepten-6-one is an intermediate for the manufacture of vitamins.

Abstract: A process for the manufacture of higher ketones by reacting an aldehyde with a ketone in the presence of hydrogen over a catalyst system which contains, firstly, oxides or salts of the rare earth metals and, secondly, metals of group VIII of the periodic table of the elements. The process gives numerous higher ketones, required, for example, as solvents for surface coatings, or as scents, with high conversions and good selectivities, and therefore more simply and more economically than conventional methods.