Abstract: The invention relates to a process for preparing optically active ?-aminoacetals by resolution of a racemic mixture or of a mixture of enantiomers via the formation of diastereoisomeric salts, and also novel intermediates in the form of diastereoisomeric salts.

Abstract: The invention relates to a process for the preparation of N-protected ?-aminoaldehydes by deacetalization of the acetal functional group of corresponding N-protected ?-aminoacetals using formic acid.

Abstract: The invention relates to a process for the synthesis of stilbene derivatives of formula (I)-(E) or (I)-(Z) in which R represents hydrogen or an OH group, by deprotection in the presence of an aluminum halide and of a tertiary amine of a compound of formula (II)-(E) or (II)-(Z) in which A represents hydrogen or an OR?1 group, and R1, R2, R3 and R?1 independently represent an alkyl or aralkyl group.

Abstract: The invention relates to a process for preparing ?-aminoacetals substantially in racemic form, comprising a step of oxidizing optically enriched ?-aminoacetals to the corresponding oximes, in the presence of a catalyst, and a step of reducing the oximes thus obtained.

Abstract: A subject-matter of the present invention is a novel process for the synthesis of (E)-stilbene derivatives targeted at obtaining in particular resveratrol and piceatannol.

Abstract: The invention relates to a process for preparing optically active ?-aminoacetals by resolution of a racemic mixture or of a mixture of enantiomers via the formation of diastereoisomeric salts, and also novel intermediates in the form of diastereoisomeric salts.

Abstract: The invention relates to a process for the synthesis of stilbene derivatives of formula (I)-(E) or (I)-(Z) in which R represents hydrogen or an OH group, by deprotection in the presence of an aluminium halide and of a tertiary amine of a compound of formula (II)-(E) or (II)-(Z) in which A represents hydrogen or an OR?1 group, and R1, R2, R3 and R?1 independently represent an alkyl or aralkyl group.

Abstract: The invention relates to a process for preparing ?-aminoacetals substantially in racemic form, comprising a step of oxidizing optically enriched ?-aminoacetals to the corresponding oximes, in the presence of a catalyst, and a step of reducing the oximes thus obtained.

Abstract: The invention relates to a process for the preparation of N-protected ?-aminoaldehydes by deacetalization of the acetal functional group of corresponding N-protected ?-aminoacetals using formic acid.

Abstract: A subject-matter of the present invention is a novel process for the synthesis of (E)-stilbene derivatives targeted at obtaining in particular resveratrol and piceatannol.

Abstract: Process for the preparation of primary amines of formula (I): where R3 represents an alkyl, cycloalkyl or aralkyl group, by reaction of a triazolium salt of formula (II): where R1 and R2 represent hydrogen or an alkyl, aralkyl or aryl group, R4 represents an alkyl or aralkyl group or a residue of an organic polymer functionalized by an alkylating group, and A? represents a halogen, alkylsulphonate, arylsulphonate, alkyl sulphate, hydrogensulphate, hemisulphate, perchlorate or hydroxide, with a hydride, in order to obtain an amine of formula (I), which is isolated, if desired, and intermediates.

Abstract: Process for the preparation of primary amines of formula (I): where R3 represents an alkyl, cycloalkyl or aralkyl group, by reaction of a triazolium salt of formula (II): where R1 and R2 represent hydrogen or an alkyl, aralkyl or aryl group, R4 represents an alkyl or aralkyl group or a residue of an organic polymer functionalized by an alkylating group, and A? represents a halogen, alkylsulphonate, arylsulphonate, alkyl sulphate, hydrogensulphate, hemisulphate, perchlorate or hydroxide, with a hydride, in order to obtain an amine of formula (I), which is isolated, if desired, and intermediates.

Abstract: Preparation process for .alpha.,.beta.-dicarbonylated compounds of formula (I) ##STR1## in which R.sub.2 =alkyl, phenyl or benzyl being able to be substituted in various ways on the cycle, or carboxylic ester, and R.sub.3 =alkyl or alkoxy or carboxylic ester in which a compound of formula (II) ##STR2## in which R.sub.1 =alkyl, or alkyl .alpha.-ketocarboxylate or carboxylic ester, and R.sub.2 and R.sub.3 have the same meanings as previously is reacted in a nitrile type solvent, with molecular oxygen in the presence of copper.sup.II nitrate or ferric chloride as catalyst, and use for obtaining ethyl .alpha.-ketobutyrate, ethyl phenyl pyruvate, ethyl pyruvate, ethyl phenylglyoxylate, butane-2,3-dione or diethyl mesoxalate.

Abstract: A process for the preparation of the enol lactone of 2-oxocyclohexylidene acetic acid wherein(i) glyoxylic acid is allowed to react with cyclohexanone in the presence of a halogen acid in order to obtain a crude reaction product B1, then(ii) said crude reaction product B1 is allowed to react, after solubilisation in an organic solvent, in the presence of a strong acid soluble in said organic solvent or of strongly acid resins, in order to obtain the enol lactone of 2-oxocyclohexylidene acetic acid which is isolated if desired,and application to the preparation of 2-coumaranone.

Abstract: Preparation process for 2-coumaranone in which glyoxylic acid, in vapor phase, is reacted with cyclohexanone, in the presence of a dehydrogenation catalyst.

Abstract: Preparation process for a hydroxyphenylacetic acid of formula (I): ##STR1## where R.dbd.H, alkyl or alkoxyl as well as its salts, in which the corresponding free or salified hydroxymandelic acid of formula (II): ##STR2## in which R has the meaning given previously and M.dbd.H, K or an ammonium group is reacted in an aqueous medium, at a temperature greater than or equal to 50.degree. C., with formic acid in the presence of catalytic quantities of an oxygenated derivative of sulphur having a degree of oxidation from 2 to 4, in order to obtain the hydroxyphenylacetic acid of formula (I) which is isolated or, if desired, is salified according to the usual methods and the hydroxyphenylacetic acid thus obtained.

Abstract: Process for obtaining an arylacetic acid of general formula (I):Ar--CHR--COOH (I)in which R=H, C.sub.1 -C.sub.4 alk, Ar=2-thienyl, 3-thienyl, 1-naphthyl, 2-naphthyl, 1-(2-methoxy naphthyl), 3,4-methylenedioxy phenyl or phenyl of general formula (II): ##STR1## in which R.sub.1 =H, OH or C.sub.1 -C.sub.4 alkoxy, R.sub.2 =H, C.sub.1 -C.sub.4 alk, C.sub.1 -C.sub.4 alkoxy or OH, as well as their alkali metal salts, by reaction in a solvent of the corresponding arylglycolic acid of general formula (III):Ar-CR(OH)--COOH (III)or one of its alkali metal salts with a hydrogen donor agent chosen from the group constituted by: formic acid, or one of its alkali metal salts, phosphonic acid, phosphinic acid, or one of their alkali metal salts, in the presence of a hydrogen transfer catalyst, which if desired is isolated or salified, and use for the preparation of certain acids of formula (I).

Abstract: Transvinylation process between vinyl acetate or vinyl propionate and a carboxylic acid of general formula (I),RCOOH (I)in which R represents a substituted or non-substituted alkyl, cycloalkyl, aralkyl or aromatic radical, in the presence of a palladium catalyst, in which the catalyst is obtained in situ, by reacting, in the reaction medium, a derivative of palladium chosen from the group constituted by palladium II acetate, nitrate or hydroxide and palladium deposited on charcoal, with a tertiary amine chosen from the group constituted by 2,2'-bipyridyl, orthophenanthroline or tetramethylethylenediamine, that the quantity of palladium used, expressed in gram-atom of palladium II per 100 moles of carboxylic acid of general formula (I) is between 0.005 and 1 and that the quantity of amine is greater than 1 and less than 10 moles per gram-atom of palladium II used and use for the preparation of certain products.

Abstract: The invention provides an improved process for the manufacture of alkyl pyruvates having general formula (I):CH.sub.3 --CO--COOR (I)where R represents a C.sub.1 to C.sub.8 alkyl radical, by controlled oxidation of the corresponding alkyl lactate.The process is characterized in that the controlled oxidation is carried out using an aqueous hydrogen peroxide solution in the presence of catalytic quantities of bromium.

Abstract: A process for preparation of substituted acetic acids having the general formula I:Ar--CHR--COOH Iin which R is selected from the group consisting in one hydrogen atom and C.sub.1 -C.sub.4 -alkyl radicals, and Ar is selected from the group consisting in radicals of aromatic nature selected from the following radicals: 2-thienyl, 2-methoxy-1-naphthyl, 3,4-methylenedioxy-phenyl, and the substituted phenyls of the general formula II: ##STR1## where R.sub.1 is selected from the group consisting in hydrogen and C.sub.1 -C.sub.4 -alkyl groups, and R.sub.