Abstract: A method for preparing a compound of formula (I) in which R1 is selected from H and alkyls, R2 is selected from H, alkyls, OR? where R? is selected from alkyls, silyls, CO-alkyl, R3 is selected from the acyl groups of the CO(R?) type, and the CO(OR?), CO(NR?R??), PO(OR?)(OR??), PO(OR?)(R??) groups where R? and R??, independently of each other, are selected from H and alkyls, R represents a C(R4)?C(R5)(R6) group where R4, R5 and R6, independently of each other, are selected from H, linear or cyclic alkyls and alkenyls, aryls, alkylaryls, or R4 and R5 together form a saturated or unsaturated, substituted or unsubstituted ring, from a compound of formula (II) or a compound of formula (III) in which, R, R1, R2 and R3 have the above definition.

Abstract: A method for preparing dehydro-cyclofarnesal from dehydro-farnesal by cyclization in the presence of an acid may include the dehydro-farnesal being obtained from the farnesal by dehydrogenation and may further includes the cyclization being carried out in the presence of an acid selected from Lewis acids, Bronstedt acids, and zeolites. The synthesis of vitamin A using this method further includes the conversion of dehydro-cyclofarnesal into vitamin A.

Abstract: A method for preparing dehydro-cyclofarnesal from dehydro-farnesal by cyclization in the presence of an acid may include the dehydro-farnesal being obtained from the farnesal by dehydrogenation and may further includes the cyclization being carried out in the presence of an acid selected from Lewis acids, Bronstedt acids, and zeolites. The synthesis of vitamin A using this method further includes the conversion of dehydro-cyclofarnesal into vitamin A.

Abstract: A method for preparing a compound of formula (I) in which R1 is selected from H and alkyls, R2 is selected from H, alkyls, OR? where R? is selected from alkyls, silyls, CO-alkyl, R3 is selected from the acyl groups of the CO(R?) type, and the CO(OR?), CO(NR?R??), PO(OR?)(OR??), PO(OR?)(R??) groups where R? and R??, independently of each other, are selected from H and alkyls, R represents a C(R4)?C(R5)(R6) group where R4, R5 and R6, independently of each other, are selected from H, linear or cyclic alkyls and alkenyls, aryls, alkylaryls, or R4 and R5 together form a saturated or unsaturated, substituted or unsubstituted ring, from a compound of formula (II) or a compound of formula (ill) in which, R, R1, R2 and R3 have the above definition.

Abstract: The invention relates to a method for preparing a compound (I) or one of the salts thereof, and the uses of said method, R1OOC—C(?X)—CHR2R3(I), wherein X is selected among O; N—R?, wherein R? is H or a C1-C6 alkyl; and N—OR? wherein R? is H, or a C1-C6 alkyl or an alkylaryl; R1 is H or a C1-C6 alkyl group; R2 is H, a C1-C6 alkyl, or an alkylaryl; and R3 is CH2SR4 or CH2SeR4, where R4 is H or a C1-C6 alkyl from a compound (II), or one of the salts thereof, R1OOC—C(?X)—CHR2R5 and R5 is H or COOR6, where R6 is H or a C1-C6 alkyl, said method being carried out in the presence of a compound (III) CH2(Y)(Z).

Abstract: The invention concerns a continuous process for manufacturing methionine by alkaline hydrolysis of methionine hydantoin in aqueous phase, removing NH3 and CO2 of the hydrolysis medium, and neutralizing the obtained methioninate salt, according to which, after removal of NH3 and CO2, the hydrolysis reaction medium is concentrated to precipitate Na2CO3, said Na2CO3 being separated then recycled for alkaline hydrolysis, the latter being carried out in the presence of NaOH and Na2CO3.

Abstract: The invention concerns a synthesis process of a compound of the following formula (I) or one of the salts thereof, wherein R represents a COOH, CH2OH 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.

Abstract: The invention relates to a method for preparing an olefine, a diene or a polyene, by catalytic conversion of at least one alcohol having a carbon chain of at least three carbon atoms and different from propan-2-ol, in the presence of at least one catalyst based of at least one phosphate of a metal or several metals M, M being chosen from among the 15 lanthanides (Lanthanum, Cerium, Praseodymium, Neodymium, Promethium, Samarium, Europium, Gadolinium, Terbium, Dysprosium, Holmium, Erbium, Thulium, Ytterbium, Lutetium), Yttrium, Scandium and Boron, and the applications of this method.

Abstract: The invention concerns a continuous process for manufacturing methionine by alkaline hydrolysis of methionine hydantoin in aqueous phase, removing NH3 and CO2 of the hydrolysis medium, and neutralizing the obtained methioninate salt, according to which, after removal of NH3 and CO2, the hydrolysis reaction medium is concentrated to precipitate Na2CO3, said Na2CO3 being separated then recycled for alkaline hydrolysis, the latter being carried out in the presence of NaOH and Na2CO3.

Abstract: The invention concerns a synthesis process of a compound of the following formula (I) or one of the salts thereof, wherein R represents a COOH, CH2OH 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.

Abstract: The invention relates to a method for preparing an olefine, a diene or a polyene, by catalytic conversion of at least one alcohol having a carbon chain of at least three carbon atoms and different from propan-2-ol, in the presence of at least one catalyst based of at least one phosphate of a metal or several metals M, M being chosen from among the 15 lanthanides (Lanthanum, Cerium, Praseodymium, Neodymium, Promethium, Samarium, Europium, Gadolinium, Terbium, Dysprosium, Holmium, Erbium, Thulium, Ytterbium, Lutetium), Yttrium, Scandium and Boron, and the applications of this method.

Abstract: The disclosure concerns a method for preparing acrolein from glycerol, according to which a dehydration of the glycerol is carried out in the presence of a catalyst MWOA, wherein MWO represents a mixture of simple oxides and/or mixed oxides of tungsten and at least one metal M selected among zirconium, silicon, titanium, aluminium and yttrium, and A represents one or several Lewis base(s), one said Lewis base being of the formula B(R1)p(R2)q(R3)r, wherein B is an element selected among C, S, P, O, N and halides, R1, R2 and R3 represent, independently of each other, H, a C1-C6 alkyl group, O, OH or OR wherein R represents a C1-C6 alkyl group, and the sum of p, q and r varies from 0 to 4.

Abstract: The disclosure concerns a method for preparing acrolein from glycerol, according to which a dehydration of the glycerol is carried out in the presence of a catalyst MWOA, wherein MWO represents a mixture of simple oxides and/or mixed oxides of tungsten and at least one metal M selected among zirconium, silicon, titanium, aluminium and yttrium, and A represents one or several Lewis base(s), one said Lewis base being of the formula B(R1)p(R2)q(R3)r, wherein B is an element selected among C, S, P, O, N and halides, R1, R2 and R3 represent, independently of each other, H, a C1-C6 alkyl group, O, OH or OR wherein R represents a C1-C6 alkyl group, and the sum of p, q and r varies from 0 to 4.

Abstract: The invention concerns a method for preparing a complex of an acid chosen from among methionine, 2-hydroxy-4-methylthiobutanoic acid (HMTBA) and lactic acid, and of at least one metal, starting from said acid and a mineral metal source, wherein the acid is caused to react with the mineral metal source in an extruder.

Abstract: The invention concerns a method for preparing a complex of an acid chosen from among methionine, 2-hydroxy-4-methylthiobutanoic acid (HMTBA) and lactic acid, and of at least one metal, starting from said acid and a mineral metal source, wherein the acid is caused to react with the mineral metal source in an extruder.

Abstract: The invention relates to a process for preparing 2-oxo-4-methylthiobutyric acid (I), its salts and its derivatives in which R represents a group chosen from COOH, COOR?, NH2, NHR? or NR?R?, where R? and R? are chosen, independently of one another, from the group of linear or branched alkyl radicals having from 1 to 12 carbon atoms and cycloalkyl radicals having from 3 to 12 carbon atoms, according to which process but-3-ene-1,2-diol (II) is catalytically and selectively oxidized to give 2-oxobut-3-enoic acid (III) and methyl mercaptan is selectively condensed with 2-oxobut-3-enoic acid (III). 2-Oxo-4-methylthiobutyric acid (I), its salts and its derivatives are used as food supplement, in particular in animal nutrition.

Abstract: The invention relates to a process for preparing 2-oxo-4-methylthiobutyric acid (I), its salts and its derivatives in which R represents a group chosen from COOH, COOR?, NH2, NHR? or NR?R?, where R? and R? are chosen, independently of one another, from the group of linear or branched alkyl radicals having from 1 to 12 carbon atoms and cycloalkyl radicals having from 3 to 12 carbon atoms, according to which process but-3-ene-1,2-diol (II) is catalytically and selectively oxidized to give 2-oxobut-3-enoic acid (III) and methyl mercaptan is selectively condensed with 2-oxobut-3-enoic acid (III). 2-Oxo-4-methylthiobutyric acid (I), its salts and its derivatives are used as food supplement, in particular in animal nutrition.

Abstract: A process for purifying an aqueous solution to obtain purified gaseous acrolein by introducing the aqueous solution into a distillation column equipped at its base with at least one boiler and at its top with at least one condenser, withdrawing a liquid mixture essentially containing water at the base of the distillation column, withdrawing a gas essentially containing acrolein and water at the top of the distillation column, cooling the gas mixture withdrawn at the top of the distillation column in the condenser, to a temperature which makes it possible to obtain, on the one hand, an aqueous condensate and, on the other hand, an acrolein-rich gas mixture, and withdrawing the acrolein-rich gas mixture.

Abstract: The invention relates to a process for preparing 2-oxo-4-methylthiobutyric acid (I), its salts and its derivatives in which R represents a group chosen from COOH, COOR?, NH2, NHR? or NR?R?, where R? and R? are chosen, independently of one another, from the group of linear or branched alkyl radicals having from 1 to 12 carbon atoms and cycloalkyl radicals having from 3 to 12 carbon atoms, according to which process but-3-ene-1,2-diol (II) is catalytically and selectively oxidized to give 2-oxobut-3-enoic acid (III) and methyl mercaptan is selectively condensed with 2-oxobut-3-enoic acid (III). 2-Oxo-4-methylthiobutyric acid (I), its salts and its derivatives are used as food supplement, in particular in animal nutrition.

Abstract: Process for the Production of 3-methylthiopropanal. A process for the production of 3-methylthiopropanal which reacting reaction medium comprising methyl mercaptan and acrolein in the presence of a catalyst comprising an organic base characterised in that the organic base is a N-alkyl morpholine compound.