Abstract: The invention relates to a process for the preparation of polyols having 3 or 4 hydroxyl groups, from an aldehyde and formaldehyde in the presence of water, followed by hydrogenation of the aldolisation product in the presence of a hydrogenation catalyst at an elevated temperature. The aledhyde is obtained by an aldolisation reaction of an aldehyde having at least two &agr;-hydrogen atoms and a formula according to R1CH2CHO, wherein R1 is selected from a group comprising hydrogen, alkyl groups having 1-7 carbon atoms which can have cycloalkyl substituents, cycloalkyl groups, aryl groups and aralkyl groups with 1-7 carbon atoms is the alkyl chain, with formaldehyde in the presence of water in an amount of 20-70 wt %, preferably 40-60 wt % and in the presence of an anion exchange resin. The hydrogenation is preferably carried out in the presence of water.

Abstract: The invention relates to a process for the preparation of neopentyl glycol by hydrogenation of hydroxypivaldehyde (HPA) in the presence of hydrogen and a hydrogenation catalyst at an elevated temperature. According to the invention, hydroxypivaldehyde is hydrogenated in the presence of a nickel-containing catalyst and at a temperature below 100° C. in a liquid phase containing a solvent an amount of 1-70% by weight and water in an amount of 0-15% by weight. Aliphatic alcohol or ether or a mixture thereof is used as solvent.

Abstract: The invention relates to a process for the preparation of polyols having 3 or 4 hydroxyl groups, from an aldehyde and formaldehyde in the presence of water, followed by hydrogenation of the aldolisation product in the presence of a hydrogenation catalyst at an elevated temperature. The aledhyde is obtained by an aldolisation reaction of an aldehyde having at least two &agr;-hydrogen atoms and a formula according to R1CH2CHO, wherein R1 is selected from a group comprising hydrogen, alkyl groups having 1-7 carbon atoms which can have cycloalkyl substituents, cycloalkyl groups, aryl groups and aralkyl groups with 1-7 carbon atoms is the alkyl chain, with formaldehyde in the presence of water in an amount of 20-70 wt %, preferably 40-60 wt % and in the presence of an anion exchange resin. The hydrogenation is preferably carried out in the presence of water.

Abstract: The invention relates to a process for the preparation of polyvalent alcohols by hydrogenation of an aldehyde. According to the invention said aldehyde is obtained by aldolisation reaction of an aldehyde containing an &agr; hydrogen atom and having the formula R1CHO, or the mixture of said aldehyde with a second different aldehyde having the formula or R2CHO, wherein R1 is selected from alkyl having 1-12 carbon atoms, cycloalkyl, aryl and aralkyl having 1-14 carbon atoms, and R2 is selected from H, alkyl having 1-12 carbon atoms, cycloalkyl, aryl and aralkyl having 1-14 carbon atoms, said aldolisation being carried out in the presence of a weak base anion exchange resin, and the hydrogenation being carried out in the presence of a solvent and a hydrogenation catalyst.