Abstract: Method which makes it possible to define, over time, the concentration of the species in a reaction medium from the infrared profiles of the products resulting from the monitoring of the reaction and from the HPLC data, without precalibration of the devices.

Abstract: Method which makes it possible to define, over time, the concentration of the species in a reaction medium from the infrared profiles of the products resulting from the monitoring of the reaction and from the HPLC data, without precalibration of the devices.

Abstract: The invention concerns a method for preparing compounds of formula (I) wherein R represents a hydrogen atom or an allyl radical containing up to 8 carbon atoms, characterised in that it consists in subjecting a compound of formula (II) wherein alc represents the residue of an alkyl radical containing up to 4 carbon atoms to the action of a compound of formula (III): RCONH2, wherein R retains its previous meaning, to obtain the compound of formula (IV) wherein R retains its previous meaning which is subjected to cyclization to obtain the desired product of formula (I).

Abstract: The invention relates to a novel process for preparing compounds of the formula (IV) or (I): from the racemic alkoxyfuranone of the formula (II): R1 and R2 being as defined in the description, to the novel compounds of the formula (IV) as well as to the intermediate compounds of this process, and to the use of the compounds of the formula (IV) or (I) in the process for the synthesis of compounds which inhibit interleukin-1beta converting enzyme.

Abstract: An isomerization method wherein a compound of formula ##STR1## wherein X and y together form a 3-oxo radical, or X is a hydrogen atom and Y is either a radical a ##STR2## where R.sub.2 is OH or O-acyl, or an O-alkyl or NH.sub.2 radical; R.sub.1 is a hydrogen atom or a methyl radical; Z is hydrogen or an acyl radical; and R is a hydrogen atom, an NH.sub.2 radical or a (CH.sub.2).sub.n Ar, NH(CH.sub.2).sub.n Ar or N.dbd.CH(CH.sub.2).sub.n Ar radical, in the form of a 10.alpha. isomer or a mixture of 10.alpha. and 10.beta. isomers, is exposed to a basic agent to give the corresponding compound of formula I in which the 10-methyl radical is in the .beta. position.

Abstract: A subject of the invention is the compounds of formula (I): ##STR1## in which R represents a carboxylic acid remainder containing up to 18 carbon atoms the products of formula (I) can be used to prepare antibiotic products.

Abstract: A process for the preparation of a compound of the formula ##STR1## comprising reacting 1R, cis 2,2-dimethyl 3-(2-oxopropyl)-cyclopropane-1-carboxylic acid with an alkali metal, alkaline-earth metal or magnesium hypohalite, and oxidizing the 1R, cis 2,2-dimethyl 3-(hydroxy-carboxy-methyl)-cyclopropane-1-carboxylic acid or its salt or lactonic form thereof thus obtained with an oxidizing agent to obtain the compound of formula I and novel intermediates.

Abstract: A subject of the invention is the compounds of formula (I): in which R represents a carboxylic acid remainder containing up to 18 carbon atoms the products of formula (I) can be used to prepare antibiotic products.