Abstract: A process for production of malic acid includes obtaining a feed that includes one or more of crude maleic anhydride, pure maleic anhydride, crude maleic acid, crude fumaric acid, pure maleic acid, pure fumaric acid, vent gas scrubber solutions from production of maleic anhydride, and vent gas scrubber solutions from production of phthalic anhydride. The feed is passed in a tubular reactor assembly to obtain a first product stream, which includes unreacted feed and malic acid. The feed is made to undergo hydration reaction in the tubular reactor assembly for a first predetermined time period, and further hydration of the first product stream is caused in a stirred tank reactor assembly for a second predetermined time period to obtain a final product stream, which includes the malic acid.

Abstract: The present invention relates to the manufacture of biobased acrylic acid from glycerol as starting material, the term “biobased acid” indicating that the acrylic acid is essentially based on a carbon source of natural origin.

Abstract: The disclosed invention is a method for manufacturing an oxidized organic compound which includes a step of forming an oxidized organic compound, in use of a fixed-bed reactor having a reaction tube packed with an oxide catalyst, by supplying at least one type of organic compound as a reaction feedstock gas and using a molecular oxygen-containing gas to carry out a catalytic gas-phase oxidation reaction; and a step of stopping the catalytic gas-phase oxidation reaction. In the manufacturing method, when stopping the catalytic gas-phase oxidation reaction, the supply of the reaction feedstock gas is stopped, after which an inert gas is supplied to the reactor, then a molecular oxygen-containing gas is supplied, subsequent to which the supply of the molecular oxygen-containing gas to the reactor is stopped.

Abstract: A process for the oxidation of alcohol and/or aldehyde groups with a peroxo compound in the presence of a heterogeneous rhenium based catalyst, and a co-catalyst. The process of the invention may, for example, be applied to the manufacture of maleic acid which can be dehydrated to lead to maleic anhydride.

Abstract: The invention relates to a process for oxidizing at least one organic substance with oxygen, which comprises the following steps: (a) adding the at least one organic substance as a liquid and an oxygenous gas stream to a first reaction stage to form a reaction mixture, at least some of the oxygen reacting with the organic compound to form a reaction product, (b) adding the reaction mixture from the first reaction stage to an adiabatically operated reaction stage in which the unconverted organic substance reacts further at least partly to give the product. The invention further relates to an apparatus for performing the process.

Abstract: An object of the present invention is to provide: a catalyst for production of acrylic acid which is a catalyst usable for production of acrylic acid and is excellent in the catalytic performances such as catalytic activity and in the physical properties such as physical strength of the catalyst itself; and a process for production of acrylic acid using this catalyst. As a means of achieving this object, a catalyst for production of acrylic acid according to the present invention is a catalyst obtained by drying a mixed liquid of starting materials including molybdenum and vanadium as essential components to give a dried material, molding the dried material with a liquid binder, and calcining the resultant molding, with the catalyst being characterized in that an ignition loss ratio of the dried material is from 5 to 40% by mass.

Abstract: Disclosed is a palladium-containing catalyst which enables to produce an ?,?-unsaturated carboxylic acid in high selectivity from an olefin or an ?,?-unsaturated aldehyde. Also disclosed are a method for producing such a catalyst and a method for producing an ?,?-unsaturated carboxylic acid using such a catalyst. Specifically disclosed is a palladium-containing catalyst containing 0.001 to 0.25 mole of antimony element to 1 mole of palladium element or a palladium-containing catalyst containing palladium element which composes a metal, tellurium element, and bismuth element.

Abstract: The subject of the present invention is a process for preparing acrolein by dehydration of glycerol in the presence of a catalyst system comprising oxygen, phosphorus and at least one metal chosen from vanadium, boron or aluminium. The process is preferably carried out in the gas phase in the presence of oxygen starting from aqueous solutions of glycerol.

Abstract: The present invention relates to a process for preparing 4-pentenoic acid, at least comprising the oxidation of a mixture (G) comprising 4-pentenal, 3-methyl-2-butanone and cyclopentene oxide, and to the use of a mixture (G) comprising 4-pentenal, 3-methyl-2-butanone and cyclopentene oxide for preparing 4-pentenoic acid. In the context of the present invention, the mixture (G) is preferably obtained as a by-product of the oxidation of cyclopentene to cyclopentanone by means of dinitrogen monoxide.

Abstract: The present invention relates to the manufacture of bioresourced acrolein and bioresourced acrylic acid from glycerol as starting material and more particularly comes within the scope of a process for the manufacture of acrolein and acrylic acid according to which the reaction for the dehydration of glycerol to give acrolein is carried out and the organic compounds which are heavier than water liable to be present in the various streams of the process arc removed, so as to obtain a stream which can be recycled to the dehydration stage without accumulation of heavy impurities, while minimizing the consumption of water and the discharge of polluted aqueous streams.

Abstract: Disclosed is a method for producing at least one of an ?,?-unsaturated aldehyde and an ?,?-unsaturated carboxylic acid from an alcohol in a liquid phase through a simple process. Namely, at least one of an ?,?-unsaturated aldehyde and an ?,?-unsaturated carboxylic acid is produced by dehydrating and oxidizing an alcohol in a liquid phase at 110 to 250° C. in the presence of molecular oxygen and a noble metal-containing catalyst. Alternatively, at least one of an ?,?-unsaturated aldehyde and an ?,?-unsaturated carboxylic acid is produced by dehydrating and oxidizing an alcohol in a liquid phase in the presence of molecular oxygen, a noble metal-containing catalyst, and an acidic substance.

Abstract: A process for producing (meth)acrylic acid, comprising a crystallizing step of supplying a cooling medium from a refrigerator to a crystallizer and returning the cooling medium from the crystallizer to the refrigerator, thereby obtaining a (meth)acrylic acid crystal from a (meth)acrylic acid-containing solution; and a melting step of supplying a heating medium from a refrigerator to the crystallizer and returning the heating medium from the crystallizer to the refrigerator, thereby melting the (meth)acrylic acid crystal; wherein the crystallizing step and the melting step are respectively performed at least once, thereby producing purified (meth)acrylic acid from a crude (meth)acrylic acid solution; temperature of the cooling medium discharged from the refrigerator is maintained constant at temperature T1; temperature of the cooling medium to be returned to the refrigerator is maintained constant at temperature T2; the temperature T2 is adjusted depending on a production amount of the purified (meth)acrylic a

Abstract: Disclosed is a palladium-containing catalyst which enables to produce an ?,?-unsaturated carboxylic acid in high selectivity from an olefin or an ?,?-unsaturated aldehyde. Also disclosed are a method for producing such a catalyst and a method for producing an ?,?-unsaturated carboxylic acid using such a catalyst. Specifically disclosed is a palladium-containing catalyst containing 0.001 to 0.25 mole of antimony element to 1 mole of palladium element or a palladium-containing catalyst containing palladium element which composes a metal, tellurium element, and bismuth element.

Abstract: The present invention provides: a palladium-containing supported catalyst which is used for producing an ?,?-unsaturated carboxylic acid from an olefin or an ?,?-unsaturated aldehyde in high selectivity; a method for manufacturing the catalyst; and a method for producing an ?,?-unsaturated carboxylic acid in high selectivity. In particular, the present invention resides in a method for manufacturing a palladium-containing supported catalyst for producing an ?,?-unsaturated carboxylic acid from an olefin or an ?,?-unsaturated aldehyde, comprising the step of reducing palladium oxide contained in a catalyst precursor wherein at least the palladium oxide is supported on a carrier. By using such a palladium-containing supported catalyst, an ?,?-unsaturated carboxylic acid is produced through liquid-phase oxidation of an olefin or an ?,?-unsaturated aldehyde with molecular oxygen.

Abstract: Disclosed is a method for producing an ?, ?-unsaturated carboxylic acid from an olefin or an ?, ?-unsaturated aldehyde, while suppressing dissolution of a silica carrier, which is a carrier for a silica-supported noble metal-containing catalyst, in a water-containing solvent. Specifically disclosed is a method for producing an ?, ?-unsaturated carboxylic acid through oxidation of an olefin or an ?, ?-unsaturated aldehyde in a water-containing solvent in the presence of a silica-supported noble metal-containing catalyst in a reactor, in which at least one of silicic acid and ions thereof is supplied into the reactor.

Abstract: Methods for making unsaturated acids using catalysts for oxidation of unsaturated and/or saturated aldehyde to unsaturated acids is disclosed where the catalyst including at least molybdenum (Mo) and phosphorus (P), where the catalyst has a pore size distribution including at least 50% medium pores and if bismuth is present, a nitric acid to molybdenum mole ratio of at least 0.5:1 or at least 6.0:1 moles of HNO3 per mole of Mo12.

Abstract: Disclosed is a palladium-containing catalyst for producing an ?, ?-unsaturated carboxylic acid from an olefin or an ?, ?-unsaturated aldehyde in high productivity. Also disclosed are a method for producing such a catalyst, and a method for producing an ?, ?-unsaturated carboxylic acid in high productivity. Specifically, a palladium-containing catalyst is produced by a method containing a step in which palladium in an oxidation state is reduced by a compound (A) which is represented by the following formula (1).

Abstract: A benzyl vinyl ether represented by the following formula is hydrolyzed in the presence of a catalyst selected among Arrhenius acids and Lewis acids to obtain 3,3,3-trifluoropropionaldehyde. Subsequently, the 3,3,3-trifluoropropionaldehyde is oxidized with an oxidizing agent. Thus, 3,3,3-trifluoropropionic acid can be more advantageously produced than in conventional techniques from an inexpensive starting material.

Abstract: Disclosed is a method for enhancing a yield of an ?,?-unsaturated carboxylic acid obtained by liquid-phase oxidation reaction of an olefin or an ?,?-unsaturated aldehyde. In particular, there is provided a method for producing an ?,?-unsaturated carboxylic acid, wherein the method includes the step of carrying out oxidation reaction of an olefin or an ?,?-unsaturated aldehyde in a liquid phase to obtain a reaction mixture containing an ?,?-unsaturated carboxylic acid and an ?,?-unsaturated carboxylic acid anhydride and the step of bringing the ?,?-unsaturated carboxylic acid anhydride into contact with an alcohol or water to obtain an ?,?-unsaturated carboxylic acid resulting from decomposition of the ?,?-unsaturated carboxylic acid anhydride.

Abstract: Disclosed is a palladium-containing catalyst for producing an ?,?-unsaturated carboxylic acid from an olefin or an ?,?-unsaturated aldehyde in high productivity. Also disclosed are a method for producing such a catalyst, and a method for producing an ?,?-unsaturated carboxylic acid in high productivity. Specifically, a palladium-containing catalyst is produced by a method containing a step in which palladium in an oxidation state is reduced by a compound (A) which is represented by the following formula (1).

Abstract: Disclosed is a method for producing an ?, ?-unsaturated carboxylic acid from an olefin or an ?, ?-unsaturated aldehyde, while suppressing dissolution of a silica carrier, which is a carrier for a silica-supported noble metal-containing catalyst, in a water-containing solvent. Specifically disclosed is a method for producing an ?, ?-unsaturated carboxylic acid through oxidation of an olefin or an ?, ?-unsaturated aldehyde in a water-containing solvent in the presence of a silica-supported noble metal-containing catalyst in a reactor, in which at least one of silicic acid and ions thereof is supplied into the reactor.

Abstract: A heteropolyacid catalyst for oxidation of isobutyraldehyde, methacrolein or mixtures or combinations thereof to methacrylic acid is disclosed where the heteropolyacid catalyst includes at least molybdenum (Mo), phosphorus (P), vanadium (V), and a first component including bismuth (Bi) and/or boron (B). The heteropolyacid catalyst can also optionally include a second component including potassium (K), rubidium (Rb), cesium (Cs), and/or thallium (Tl) and optionally a third component including antimony (Sb), cerium (Ce), niobium (Nb), indium (In), iron (Fe), chromium (Cr), cobalt (Co), nickel (Ni), manganese (Mn), arsenic (As), silver (Ag), zinc (Zn), germanium (Ge), gallium (Ga), zirconium (Zr), magnesium (Mg), barium (Ba), lead (Pb), tin (Sn), titanium (Ti), aluminum (Al), silicon (Si), tantalum (Ta), tungsten (W), and/or lanthanum (La). The heteropolyacid catalyst can also include an ammonium-containing compound designed to increase a value of medium pores in the final heteropolyacid catalyst.

Abstract: Disclosed are a Mo—Bi—Nb—Te based composite metal oxide; and a process for producing (meth)acrylic acid from at least one reaction material selected from the group consisting of propylene, propane, isobutylene, t-butyl alcohol and methyl-t-butyl ether, wherein the Mo—Bi—Nb—Te based composite metal oxide is used as a catalyst. Also, disclosed is a process for producing (meth)acrylic acid comprising a first step of producing (meth)acrolein as a main product from at least one reaction material selected from the group consisting of propylene, propane, isobutylene, t-butyl alcohol and methyl-t-butyl ether, and a second step of producing (meth)acrylic acid from the (meth)acrolein, wherein yield of (meth)acrylic acid in the product of the first step is 20 mole % or higher.

Abstract: Disclosed is a method for enhancing a yield of an ?,?-unsaturated carboxylic acid obtained by liquid-phase oxidation reaction of an olefin or an ?,?-unsaturated aldehyde. In particular, there is provided a method for producing an ?,?-unsaturated carboxylic acid, wherein the method includes the step of carrying out oxidation reaction of an olefin or an ?,?-unsaturated aldehyde in a liquid phase to obtain a reaction mixture containing an ?,?-unsaturated carboxylic acid and an ?,?-unsaturated carboxylic acid anhydride and the step of bringing the ?,?-unsaturated carboxylic acid anhydride into contact with an alcohol or water to obtain an ?,?-unsaturated carboxylic acid resulting from decomposition of the ?,?-unsaturated carboxylic acid anhydride.

Abstract: The object of the present invention is to provide a method for producing an ?,?-unsaturated carboxylic acid in higher selectivity. The present invention resides in a method for producing an ?,?-unsaturated carboxylic acid from an olefin or an ?,?-unsaturated aldehyde in liquid phase by using a noble metal-containing catalyst and by causing a compound (A) having an acid dissociation exponent (pKa) of less than 4 to be present in the liquid phase.

Abstract: The present invention is to provide a method for producing the desired optically active ?-amino acid derivatives of high optical purities in high yields, without requiring a step of deprotection. More particularly, the present invention relates to a method for producing an optically active ?-amino acid derivative or a salt thereof represented by the formula (2): which comprises reacting an ?,?-unsaturated carboxylic acid derivative or a salt thereof represented by the formula (1): with an amines or a salt thereof in the presence of a chiral catalyst and in the presence or absence of an acid.

Abstract: The present invention provides a method for producing methacrylic acid through gas-phase catalytic oxidation of methacrolein or a methacrolein-containing gas with molecular oxygen or a gas containing molecular oxygen by the use of a fixed-bed multitubular reactor comprising a plurality of reaction tubes each having a catalyst layer therein, wherein the above catalyst layer is divided in the direction of the tube axis of a reaction tube into two or more layers, to thereby provide a plurality of reaction zones, and the catalyst is caused to be present in the catalyst layer in such a way that a reaction load ratio CRc(i) per unit mass of the catalyst in each reaction zone becomes 0.8 to 1.0.

Abstract: In producing optically-active amino acid benzyl esters by reacting optically-active amino acids with benzyl alcohols, hydrazines are present in the reaction system, or the compounds are reacted in the absence of oxygen, or the compounds are reacted in the absence of oxygen while hydrazines are present in the reaction system. The processes are simple and give optically-active amino acid benzyl esters of high optical purity.

Abstract: The invention relates to a method for producing aliphatic carboxylic acids from aldehydes by means of oxidation with oxygen or gases containing oxygen. This novel process is carried out in at least two stages at different temperatures, preferably in the absence of catalysts.

Abstract: The invention relates to a non-catalysed method for the synthesis of straight-chain aliphatic carboxylic acids by oxidation of straight-chain aldehydes with oxygen-containing gas mixtures. The invention is characterised in that during the novel process of oxidation branched aldehydes are present in the reaction mixture.

Abstract: The present invention provides a method for stabilizing waste oil which is taken of each chemical apparatus of the manufacturing line of (meth)acryl acid and/or ester thereof, and treating the waste oil such as draining it out of the production apparatus, for example, a distillation tower from its bottom, sending and transporting it by a pump through a pipeline, and storing it in a storage tank in a simple manner while keeping the waste oil in a stable state. The waste oil can be stabilized by coexisting with solvent. The solvent used in the present invention is typically at least one selected from the group consisting of water, alcohol, ether, carboxylic acid, ketone, aromatic hydrocarbons, and aliphatic hydrocarbons.

Abstract: A method of producing acrylic acid using a catalyst for acrolein oxidation reaction. Metallic salt components of the catalyst including molybdate, vanadate and tungstate are dissolved in water. An additional metallic salt component of the catalyst is added to the aqueous solution of the salts to form a suspension of the catalyst. In the suspension, the total weight of water is about 0.8 to about 5 times of the total weight of the metallic salts in the catalyst. This method of preparing suspension minimizes the amount of water required to dissolve the metallic salts, which reduces the amount of time and energy to be used in evaporating water from the suspension in the following step of obtaining catalyst. Additionally, in obtaining catalyst from the suspension prepared by this method, it is possible to avoid the deterioration of the catalytic performance since less heat is required to evaporate the water. Disclosed also is a method of producing a carrier-retained catalyst.

Abstract: This invention relates to a process for producing one or more organic acids in high purity which process comprises (i) oxidizing in a liquid oxidation reactor one or more organic liquids with essentially pure oxygen or oxygen-enriched air containing at least about 50% oxygen, at a temperature sufficiently stable to prevent cycling of reaction rate, to produce a crude reaction product fluid, and (ii) refining said crude reaction product fluid to give said one or more organic acids in high purity. The oxidation temperature is preferably controlled to within about ±3° C. of a target temperature. The organic acids described herein is useful in a variety of applications, such as intermediates in the manufacture of chemical compounds, pharmaceutical manufacture and the like.

Abstract: The present invention provides a method of producing easily and in a high yield a threo-2-hydroxy-3-nitrobutanoic acid compound or a mixture of a threo- and an erythro-2-hydroxy-3-nitrobutanoic acid compounds, this mixture having an erythro compound:threo compound ratio of about 1:1, which method includes reacting, in a solvent, a 2-hydroxy-3-nitrobutanoic acid compound having the formula (I) 1

Abstract: Bioactive fucopeptides and libraries of fucopeptides having advanced activities against P-selectin as sialyl Lewis X mimetics with IC.sub.50 values in the low mM range are synthesized by solid phase synthesis using para-acyloxymethylenzlidene acetal (p-AMBA) as an anchoring group. A rapid parallel synthesis is employed which proceeds with a bi-directional functionalization of glycosylated amino acid derivatives.

Abstract: The present invention is a method to produce an unsaturated carboxylic acid which includes the steps of: providing an epoxy compound; contacting the epoxy compound with carbon monoxide in the presence of a catalytically effective amount of a catalyst system comprising tin and cobalt under conditions effective for carbonylation of the epoxy; and recovering a .alpha.-.beta. unsaturated carboxylic acid product. The preferred epoxy is ethylene oxide which is reacted to acrylic acid by the method of the present invention.

Abstract: An oxide catalyst comprising the elements Mo, V and Nb with small amounts of phosphorus, boron, hafnium, Te and/or As. The modified catalyst provides both higher selectivity and yield of acetic acid in the low temperature oxidation of ethane with molecular oxygen-containing gas. A process for the higher selective production of acetic acid by the catalytic oxidation of ethane with oxygen, in the presence of the improved catalyst.

Abstract: Compounds of the formula ##STR1## wherein A is the group ##STR2## R.sup.1 is hydrogen, amino, protected amino, acylamino or lower alkyl optionally substituted by aryl, hydroxy, protected hydroxy, amino, protected amino, acylamino, maleimido, succinimido, naphthalimido, 2,3-dihydro-1,3-dioxo-1H-benz[d,e]isoquinol-2-yl, carboxy, protected carboxy, carbamoyl, mono(lower alkyl)carbamoyl, di(lower alkyl)carbamoyl, di(lower alkyl)amino, carboxy-lower alkanoylamino, pyrrolidino or morpholino; R.sup.2 is hydrogen or lower alkyl optionally substituted by aryl, amino, protected amino, di(lower alkyl)- amino, guanidino, carboxyl, protected carboxyl, carbamoyl, mono(lower alkyl) carbamoyl, di(lower alkyl)carbamoyl, di(lower alkoxy)phosphinyl, dihydroxyphosphinyl, pyrrolidino, piperidino or morpholino; R.sup.3 is hydrogen or lower alkyl optionally substituted by hydroxy, protected hydroxy, amino or protected amino; R.sup.4 is hydrogen, hydroxy, lower alkoxy or benzyloxy; and R.sup.

Abstract: A method of preparing compactin and mevinolin, ketoacid, enone, and glutarate analogs thereof, and related compounds. The compounds are prepared in substantially enantiomerically pure form using a structurally convergent synthesis. Total syntheses of (+)-compactin, (+)-mevinolin and related compounds are provided. Novel compounds are identified, several of which show significant anti-hypercholesterolemic activity.

Abstract: A method to oxidize an oxidizable component in a liquid phase with an oxygen-containing gas is disclosed. The method comprises mixing the liquid phase and gas phase in a reactor with a rotating agitator element operated at constant power.

Abstract: A novel process for producing oxygen-containing organic compounds with high selectivity and good yield by oxidizing organic compounds under mild conditions is provided, which process comprises using as a catalyst for the oxidation, a complex (M.sub.m X.sub.n.L.sub.l) consisting of a transition metal compound (M.sub.m X.sub.n) and an organic phosphorous compound (L) as a ligand, wherein M represents a transition metal belonging to group I, group IV.about.VII or iron group in group VIII of the periodic table; X represents an anion such as a halogen; ligand L represents an organic phosphorous compound; and m and n mean a number of the atomic valence of said transition metal (ion) M and said anion X, respectively, and l means a number of said ligand.

Abstract: Carboxylic acids having the general formula:R--COOHwherein R is selected from the group consisting of aryl, aralkyl, aralkenyl, aralkynyl, heteroaryl, heteroarylalkyl, heteroarylalkenyl, heteroarylalkynyl, alkyl, alkenyl and alkynyl, optionally substituted by inert or non-reactive substituents under the reaction conditions, are obtained by oxidation of the corresponding aldehydes with an alkali metal or alkaline-earth metal chlorite in the presence of hydrogen peroxide and in an aqueous-organic solvent. The resulting carboxylic acids are utilizable as intermediates for preparing fine chemicals in known ways.

Abstract: A process for the production of carboxyl compounds such as caprolactones, in which the corresponding carbonyl compounds are oxidized with hydrogen peroxide in the presence of a catalyst in a substantially anhydrous liquid medium. The water formed by the reaction and any water introduced into the reaction mixture are removed from the reaction mixture.

Abstract: In the process for oxidizing methacrolein to a methacrylic acid salt with an oxidizing gas in a strongly alkaline medium at a temperature of 0 to 100.degree. C. and in the presence of a finely divided silver catalyst and recovering methacrylic acid by acidification, the improvement which comprises carrying out said oxidation in the presence of a small amount of dissolved alkali metal carbonate.

Abstract: Primary and secondary unsaturated alcohols are converted to their corresponding aldehydes and/or carboxylic acids and ketones respectively with alkali metal (per) halate, preferably sodium periodate, in the presence of ruthenium catalyst. The process is particularly useful in the oxidation of chrysanthemyl alcohol. Any unconverted intermediate aldehyde formed may be converted to the acid by recycling or by a separate oxidation step.

Abstract: Process for the liquid phase oxidation of an unsaturated lower aliphatic aldehyde to the corresponding carboxylic acid wherein the oxidation is carried out by passage of an oxygen-containing gas through a liquid medium containing the unsaturated aldehyde and a fluorine-containing organic compound.

Abstract: A process for producing a perfluorocarboxylic acid comprises reacting a perfluoroalkyl olefin with ozone to produce a perfluoroalkyl ozonide and a perfluoroalkyl aldehyde and converting said perfluoroalkyl ozonide and perfluoroalkyl aldehyde to perfluorocarboxylic acid with an oxidizing agent.

Abstract: A method of preparing methacrylic acid, which comprises liquid-phase oxidation of alpha-methylacrolein with an oxygen-containing gas in a medium of an organic solvent at a temperature ranging from 50.degree. to 100.degree. C and under a pressure of from 1 to 50 atm in the presence of a heterogeneous catalyst such as borides, carbides or nitrides of elements pertaining to Groups IVB-VB of the periodic system, or aluminum boride, carbide or nitride and in the presence of a polymerization inhibitor, whereafter the desired product is separated from the resulting reaction mixture. The method according to the present invention makes it possible to produce methacrylic acid with a high selectivity (up to 86% as calculated for the reacted alpha-methylacrolein). Conversion degree of the starting aldehyde is as high as 55%. There is no formation of polymeric products during the oxidation process.

Abstract: A process for the preparation of acrylic acid or methacrylic acid which comprises catalytically decomposing or converting in the presence of tellurium the peroxide (peroxy) compounds contained in the oxidate solution derived from the autoxidation of acrolein or methacrolein, particularly, the conversion of permethacrylic acid and methacrolein monopermethacrylate to methacrylic acid.

Abstract: A process for the liquid phase oxidation of .alpha.,.beta.-unsaturated aliphatic aldehydes, such as methacrolein and the in situ decomposition or conversion of unsaturated peroxy (peroxide) compounds formed during the oxidation to the corresponding .alpha.,.beta.-unsaturated aliphatic carboxylic acids which comprises passing oxygen or an oxygen-containing gas such as air through an inert solvent solution of the unsaturated aldehyde at a suitable temperature and pressure in the presence of an organic or inorganic zinc salt catalyst.