Abstract: Process for the preparation of ketone derivatives of isomannide and of isosorbide, wherein an aqueous solution of isomannide or of isosorbide comprising an electrolyte, particularly an alkali halide, preferably a bromide and, more preferably still, sodium bromide, are subjected to anodic electrooxidation.

Abstract: The invention concerns a process transforming an aldehyde into a corresponding alkene, of the type wherein the aldehyde is placed in the presence of a phosphoric reagent and a base in an organic solvent.The process consists in using an alcohol as the solvent and as a base a mineral base which in an aqueous medium evinces a basic strength equal to or less than that of the hydroxide ion, or a strongly basic organic base of the amine family, and in limiting the hydration rate of the reaction medium to a value at most of 10 moles of water per mole of aldehyde.

Abstract: The present invention relates to hydrogenation and hydroformylation catalysts based on a binuclear rhodium complex having the formula: ##STR1## wherein X and X' can be the same or different; when X and X' are the same they are organic tertiary phosphite groups and when different X is a CO group and X' is an organic tertiary phosphite group or an aromatic phosphine group, and SY and SY' are thiolato groups. The invention also comprises the processes of hydroformylation and hydrogenation using such catalytic complex.

Abstract: The invention relates to a process for converting an aldehyde into a corresponding alkene and of the type wherein the aldehyde is placed in the presence of a phosphoric reagent and a base in solution in an organic aprotic solvent; the process comprising using a mineral base evincing in an aqueous medium a basic force less than or equal to that of the hydroxide ion or a strongly basic organic base of the nitrogen compounds family and adjusting the hydration rate of the reaction medium in such a manner that there are about 0.5 to 5 moles of water per mole of aldehyde.

Abstract: The invention relates to a process for manufacturing 5-hydroxymethylfurfural.This process comprises decomposition of a hexose in a reaction medium constituted by water and an organic solvent, by heating to a temperature below 100.degree. C., situated especially in the range from 70.degree. to 95.degree. C., in the presence of a solid catalytic support, especially an exchange resin with a cationic function.5-hydroxymethylfurfural is applied in numerous syntheses.

Abstract: The present invention relates to hydrogenation and hydroformylation catalysts based on a binuclear rhodium complex having the formula: ##STR1## wherein X and X' can be the same or different; when X and X' are the same they are organic tertiary phosphite groups and when different X is a CO group and X' is an organic tertiary phosphite group or an aromatic phosphine group, and SY and SY' are thiolato groups. The invention also comprises the processes of hydroformylation and hydrogenation using such catalytic complex.