The invention relates to a method for catalytically producing an alkyl formate, wherein at least one alpha-hydroxy aldehyde, at least one alpha-hydroxy carboxylic acid, at least one carbohydrate, and/or at least one glycoside is reacted by means of a vanadium-oxygen compound, which contains vanadium in the oxidation stage +IV or +V, or a salt thereof as a catalyst in the solution, wherein the solution contains an alkanol, and the alkyl formate produced as a reaction product is separated from at least one other resulting reaction product. The catalyst which is reduced during the catalytic reaction is restored to its starting state in an oxidation process.

The invention concerns a synthesis process of a compound of the following formula (I) or one of the salts thereof,

##STR00001## wherein R represents a COOH, CH.sub.2OH or CHO group, comprising the step according to which the but-3-ene-1,2-diol (BDO) is subjected to an oxidation in the presence of a catalyst, said catalyst comprising an active phase based on at least one noble metal selected from palladium, gold, silver, platinum, rhodium, osmium, ruthenium and iridium, and a support containing alkaline sites.

The invention also concerns the application of this reaction to the preparation of bioavailable compounds of methionine used, in particular, in animal nutrition.

The invention concerns a synthesis process of a compound of the following formula (I) or one of the salts thereof,

##STR00001## wherein R represents a COOH, CH.sub.2OH or CHO group, comprising the step according to which the but-3-ene-1,2-diol (BDO) is subjected to an oxidation in the presence of a catalyst, said catalyst comprising an active phase based on at least one noble metal selected from palladium, gold, silver, platinum, rhodium, osmium, ruthenium and iridium, and a support containing alkaline sites.

The invention also concerns the application of this reaction to the preparation of bioavailable compounds of methionine used, in particular, in animal nutrition.

The invention concerns a synthesis process of a compound of the following formula (I) or one of the salts thereof,

##STR00001## wherein R represents a COOH, CH.sub.2OH or CHO group, comprising the step according to which the but-3-ene-1,2-diol (BDO) is subjected to an oxidation in the presence of a catalyst, said catalyst comprising an active phase based on at least one noble metal selected from palladium, gold, silver, platinum, rhodium, osmium, ruthenium and iridium, and a support containing alkaline sites.

The invention also concerns the application of this reaction to the preparation of bioavailable compounds of methionine used, in particular, in animal nutrition.

The invention relates to a process for obtaining a formate from a reaction mixture (10) in which a polyoxometallate ion, which acts as a catalyst, is in contact with an organic material at a temperature below 120° C. to produce formic acid in an aqueous solution, with the following steps. a) separating a mixture of formic acid and water from the reaction mixture by reverse osmosis and/or as vapor (18), the vapor (18) subsequently being condensed, and b) reacting the formic acid with a hydroxide (24) in aqueous solution to produce a solution of a formate.

The invention relates to a process for obtaining a formate from a reaction mixture (10) in which a polyoxometallate ion, which acts as a catalyst, is in contact with an organic material at a temperature below 120° C. to produce formic acid in an aqueous solution, with the following steps. a) separating a mixture of formic acid and water from the reaction mixture by reverse osmosis and/or as vapor (18), the vapor (18) subsequently being condensed, and b) reacting the formic acid with a hydroxide (24) in aqueous solution to produce a solution of a formate.

A process for preparing a carboxylic acid, including a step of bringing at least one vicinal diol or at least one vicinal polyol into contact with an atmosphere including oxygen, and a catalyst, and in the absence of additional solvent.

A process for preparing a carboxylic acid, including a step of bringing at least one vicinal diol or at least one vicinal polyol into contact with an atmosphere including oxygen, and a catalyst, and in the absence of additional solvent.

A process for preparing a carboxylic acid, including a step of bringing at least one vicinal diol or at least one vicinal polyol into contact with an atmosphere including oxygen, and a catalyst, and in the absence of additional solvent.

Processes for separating a di-carboxylic acid or salt thereof from a mixture containing the di-carboxylic acid or salt thereof and one or more other components are provided. Also separation media useful for these separation processes is provided. In particular, processes for preparing an aldaric acid are described, such as glucaric acid from glucose, which includes separating the aldaric acid from the reaction product. Also, various glucaric acid products are described.