Abstract: Unsaturated esters of carboxylic acids are prepared by reacting olefines or cycloolefines with carboxylic acids and oxygen in the gaseous phase in the presence of a catalyst containing noble metal salts or noble metals of the VIII.sup.th group of the Periodic System and alcali metal salts and/or alcaline earth metal salts, as activators the content of noble metal being in the range of from 1.2 to 5% by weight and the proportion of the metal fraction of each individual activator to the noble metal content being in the range of from 0.5 to 1 to 3:1.

Abstract: Vinylacetic acid and optionally .gamma.-butyrolactone are prepared by reacting an allyl compound substituted by oxygen functions with carbon monoxide in the presence of a heavy metal catalyst. When the reaction is carried out with an allyl ether or a carboxylic acid allyl ester, water is added. Vinylacetic acid is obtained in a very good yield in simple and economic manner.

Abstract: Process for the preparation of alkenyl esters of carboxylic acids in the gaseous phase from carboxylic acids, olefins and oxygen or oxygen containing gases in the presence of palladium carboxylate catalysts; the carboxylic acid concentration in the feed gas being lower in the starting period of the process than the intended final concentration, and subsequently being increased either continuously or stepwise until the final concentration is attained.

Abstract: Process for the manufacture of a molecular compound of sorbic acid -- potassium sorbate by means of crystallization from a solution of sorbic acid and potassium sorbate.

Abstract: .gamma.-BUTYROLACTONE, WHICH IS AN IMPORTANT PRELIMINARY PRODUCT FOR THE PREPARATION OF BUTANEDIOL-(1,4) AND OF PYRROLIDONE, IS MANUFACTURED BY CATALYTIC HYDROGENATION OF MALEIC ACID, MALEIC ACID ANHYDRIDE, SUCCINIC ACID, SUCCINIC ACID ANHYDRIDE, OR FUMARIC ACID, OR OF A MIXTURE OF TWO OR MORE OF THESE COMPOUNDS, USING A CATALYST CONTAINING A MIXTURE OF AN ELEMENT OF THE VIII.sup.th subgroup of the periodic system of elements or of one of its compounds with an element of the I.sup.st subgroup of the periodic system of elements or of one of its compounds. The process is highly selective, and the yields of .gamma.-butyrolactone are, therefore, excellent.

Abstract: A process for the preparation of a palladium catalyst for the oxacylation of olefins in the gaseous phase, which comprises impregnating a catalyst carrier with a solution of a palladium compound drying the catalyst at a temperature of below 90.degree. C until a residual solvent content of less than 8% by weight is attained, and reducing the impregnated catalyst with a gas mixture of inert gas and reducing agent.

Abstract: Process for regenerating palladium carrier catalysts for the oxacylation of olefins in the gaseous phase by treating the exhausted catalyst with a fatty acid blended with nitric oxides, nitric acid, peroxides or per-acids, by subsequent drying at temperatures below 90.degree. C and evaporation of the fatty acid to a residual content of below 8 weight %.

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.

Abstract: Process for purifying sorbic acid by recrystallization from aqueous solutions of an alkali metal or ammonium salt of a carboxylic acid or phosphoric acid. Impurities may be eliminated in addition by means of an adsorption agent.

Abstract: Vinylacetic acid and optionally .gamma.-butyrolactone are prepared by reacting an allyl compound substituted by oxygen functions with carbon monoxide in the presence of a heavy metal catalyst. When the reaction is carried out with an allyl ether or a carboxylic acid allyl ester water is added. Vinylacetic acid is obtained in a very good yield in simple and economic manner.

Abstract: Improvement of a process for the oxacylation of olefins in the gaseous phase in the presence of carrier catalysts containing palladium salts and additives by adding a barium carboxylic acid aurate the carboxylic acid part of which contains from 2 to 10 carbon atoms.

Abstract: An improved process for oxacylating olefins in the gaseous phase which comprises using a supported catalyst comprising palladium and a carrier having a total pore volume of from 0.4 to 1.2 ml/g, less than 10% of the total pore volume being attributable to micropores having a diameter of less than 30 A. Catalysts of this type are much more efficient than conventional catalysts.

Abstract: Process for the continuous preparation of hydroxypivalaldehyde by the reaction of isobutyraldehyde with aqueous formaldehyde in a cascade of stirred vessels in the presence of an alcohol and of an alkali metal hydroxide as a catalyst.

Abstract: Process for preserving bread and bakery products with sorbic acid by adding to the dough before baking a coarsely crystalline sorbic acid.