Abstract: Higher &agr;,&bgr;-unsaturated alcohols are prepared by monoethynylation of a ketone by the NH3/KOH method, if desired hydrogenation of the acetylene alcohol in the presence of hydrogen over a Pd-containing thin layer catalyst, purifying distillation of the hydrogenation product, preferably in a dividing wall column with recirculation of the unreacted ketone to the ethynylation step, and, if desired, preparation of higher alcohols having in each case 5 more carbon atoms in the chain by reacting the alcohols prepared by monoethynylation and, if desired, partial hydrogenation with alkyl acetoacetates diketene in a Carroll reaction to form ketones and using these as starting materials for the steps ethynylation, optional hydrogenation and fractional distillation.

Abstract: A reflection column which contains liquid distributors having at least 500 drip points/m2, which are arranged at an angle of about 90° C. to cloth layers of packing elements located immediately therebelow; and a combination of insulation and protective heating. The column is advantageously used for the rectification of mixtures of high-boiling air- or temperature-sensitive substances requiring effective separation efficiency.

Abstract: Higher &agr;,&bgr;-unsaturated alcohols are prepared by monoethynylation of a ketone by the NH3/KOH method, if desired hydrogenation of the acetylene alcohol in the presence of hydrogen over a Pd-containing thin layer catalyst, purifying distillation of the hydrogenation product, preferably in a dividing wall column with recirculation of the unreacted ketone to the ethynylation step, and, if desired, preparation of higher alcohols having in each case 5 more carbon atoms in the chain by reacting the alcohols prepared by monoethynylation and, if desired, partial hydrogenation with alkyl acetoacetatesor diketene in a Carroll reaction to form ketones and using these as starting materials for the steps ethynylation, optional hydrogenation and fractional distillation.

Abstract: Alkenes are prepared by partial hydrogenation of alkynes in the liquid phase at from 20 to 250° C. and hydrogen partial pressures of from 0.

Abstract: Process for the continuous preparation of unsaturated ketones of the formula I where the dashed line can be an additional C—C bond, R1 is an alkyl, and R2 is an aliphatic hydrocarbon having from 1 to 37 carbons, a cycloalkyl or a cycloalkylalkyl, by reacting an unsaturated alcohol of the formula II  with an alkyl acetoacetate of the formula III where R3 is an alkyl having from 1 to 5 carbons, in the presence or organic aluminum compounds as catalyst.

Abstract: Alkenes are prepared by partial hydrogenation of alkynes in the liquid phase at from 20 to 250° C. and hydrogen partial pressures of from 0.

Abstract: The present invention relates to a process for preparing 3,5, 5-trimethylcyclohex -2-ene-1,4-dione (oxoisophorone; OIP) by oxidation of 3,5,5-trimethylcyclohex-3-en-1-one (&bgr;-isophorone, &bgr;-IP) with molecular oxygen in the presence of a solvent, of a base and of a manganese salen derivative as catalyst.

Abstract: The present invention relates to a process for preparing 3,5,5-trimethylcyclohex-2-ene-1,4-dione (oxoisophorone; OIP) by oxidation of 3,5,5-trimethylcyclohex-3-en-1-one (&bgr;-isophorone, &bgr;-IP) with molecular oxygen in the presence of a solvent, of a base and of a transition metal salen derivative as catalyst and of an additive.

Abstract: Process for isolating pure substances from of mixtures of high-boiling air- and/or temperature-sensitive substances which require a high separation efficiency, by rectification under medium vacuum in columns containing metal cloth packings with ordered structure using channel liquid distributors with 500 or more drip points/m.sup.2, which are arranged at an angle of 90.degree. to the cloth layers of the packing elements located immediately below the distributors, in which two or more of the packing elements underneath the liquid distributors have only a very small height, which ensure virtual exclusion of air and are designed so that no heat exchange through the column wall can take place during the rectification. The patent also relates to packed columns which can be used for this process and to the use of this process and these columns for the final purification of vitamin E acetate by distillation.

Abstract: A process for preparing chromanol derivatives of the formula I ##STR1## where n is from 1 to 10,R.sup.1, R.sup.2,R.sup.3, R.sup.4 independently of one another are hydrogen or C.sub.1 -C.sub.4 alkyl,R.sup.5 is hydrogen, C.sub.1 -C.sub.4 alkyl, C.sub.6 -C.sub.10 aryl, C.sub.7 -C.sub.18 aralkyl, C.sub.7 -C.sub.18 alkylaryl, C.sub.1 -C.sub.22 acyl, or a group protecting the hydroxyl,by reduction of the corresponding 4-oxochromanol derivatives of the formula II ##STR2## comprises reacting the 4-oxochromanol derivatives of the formula II with metallic zinc in the presence of an acid or an acid mixture.Compounds of the formula I having C.sub.1 -C.sub.22 acyl as radical R.sup.5 can also be prepared by the above-described reduction of the compounds of the formula II with hydrogen as radical R.sup.5 and simultaneous or subsequent esterification.

Abstract: A process for preparing .gamma.,.delta.-unsaturated ketones of the general formula I ##STR1## by reacting an allyl alcohol of the general formula II ##STR2## in which R.sup.1 is H or a hydrocarbon radical having 1 to 20 carbon atoms, with diketene or an alkyl acetoacetate of the general formula III ##STR3## in which R.sup.2 is alkyl having 1 to 4 carbon atoms in an unmodified or modified Carroll reaction in the presence of an aluminum catalyst, wherein aluminum compounds which are stable liquids at room temperature, or a mixture of such aluminum compounds, which comprise at least one radical formed from an alkyl acetoacetate and 1 or 2 alkoxy radicals, or else comprise exclusively radicals formed from alkyl acetoacetates, which are esterified with sec-butanol or isobutanol, or else are esterified with at least two different alcohols, are used as aluminum catalyst.

Abstract: A process for preparing .alpha.-tocopherol or .alpha.-tocopheryl acetate by reacting 2,3,5-trimethylhydroquinone with isophytol or phytol in the presence of a zinc halide condensation catalyst and a proton donor in a solvent with or without subsequent esterification with acetic anhydride, which comprisesA. carrying out the reaction in a nonpolar solvent which is only slightly water-miscible, if at all andB. introducing the required zinc halide into the reaction in the form of a mixture of from 1 to 4 mol of water per mol of zinc halide.The possibility of introducing the zinc halide required in the process according to the invention in the form of a mixture of zinc halide and water which can be readily handled and metered at from 50 to 200.degree. C.

Abstract: Packing elements with a low pressure drop for mass transfer column internals of the internal diameter of the column and of a height of from 40 to 300 mm made of dimensionally stable layers, which have an ordered structure and are in mutual contact, of cloth material or cloth-like material with a specific surface area of from 100 to 2000 m.sup.2 /m.sup.3, whereina) the shaped layers of cloth material or cloth-like material, preferably made of metal cloth, which are in mutual contact are arranged so that they form a multiplicity of narrow flow channels, preferably virtually triangular, virtually rectangular or else virtually equilateral hexagonal flow channels, in which the angle of inclination of the serration of the individual cloth layers of the packing to the column axis is only 0 to 25.degree., preferably 3 to 14.degree.

Abstract: 2,3,5-Trimethyl-p-benzoquinone is prepared by oxidation of trimethylphenol with oxygen or an oxygen-containing gas in the presence of a catalyst containing a copper(II) halide in a two-phase reaction medium consisting of water and an aliphatic alcohol at elevated temperatures by a process in which the reaction is carried out in a mixture of water and a saturated aliphatic alcohol of 12 to 18 carbon atoms, having a flashpoint greater than 120.degree. C., such as 1-dodecanol, 1-tetradecanol, 1-hexadecanol or 1-octadecanol, in particular 1-dodecanol, and at from 60.degree. to 100.degree. C.Particularly good yields of TMQ are obtained if the reaction is carried out in the presence of a copper(II) halide, such as CuCl.sub.2 or CuBr.sub.2, and of an alkaline earth metal halide, in particular CaCl.sub.2 or MgCl.sub.2, or of an alkali metal halide, in particular LiCl or NaCl, as the catalyst system.