Abstract: The present invention provides a process for preparing ?-caprolactone in a purity of more than 99% by cyclizing 6-hydroxycaproic esters in the liquid phase at from 150 to 400° C. and from 1 to 1020 hPa abs., and removing and condensing the compounds which are volatile under cyclization conditions, which comprises thermally treating the remaining bottom product of the cyclization in at least one further reactor, removing and condensing volatile compounds and obtaining ?-caprolactone by distillation from the condensates.

Abstract: The present invention provides a process for preparing ?-caprolactone in a purity of more than 99% by cyclizing 6-hydroxycaproic esters in the liquid phase at from 150 to 400° C. and from 1 to 1020 hPa abs., and removing and condensing the compounds which are volatile under cyclization conditions, which comprises thermally treating the remaining bottom product of the cyclization in at least one further reactor, removing and condensing volatile compounds and obtaining ?-caprolactone by distillation from the condensates.

Abstract: The invention relates to a process for preparing polymethylol compounds of the formula (I) where the radicals R are each, independently of one another, a further methylol group or an alkyl group having from 1 to 22 carbon atoms or an aryl or aralkyl group having from 6 to 22 carbon atoms, by condensation of aldehydes having from 2 to 24 carbon atoms with formaldehyde in an aldol reaction using tertiary amines as catalyst to form alkanals of the formula (II) where the radicals R each independently have one of the abovementioned meanings, and subsequent hydrogenation of the latter. The particular inventive feature of this process is that the aldol reaction is carried out using an aqueous formaldehyde solution having a formic acid content of <150 ppm and preferably <100 ppm. In this way of carrying out the process, the formation of by-products can advantageously be prevented in a targeted manner and the yield of the desired polymethylol compound can thereby be increased.

Abstract: The invention relates to a process for preparing polymethylol compounds of the formula (I) (HOCH2)2—C—R2 ??(I) where the radicals R are each, independently of one another, a further methylol group or an alkyl group having from 1 to 22 carbon atoms or an aryl or aralkyl group having from 6 to 22 carbon atoms, by condensation of aldehydes having from 2 to 24 carbon atoms with formaldehyde in an aldol reaction using tertiary amines as catalyst to form alkanals of the formula (II) where the radicals R each independently have one of the abovementioned meanings, and subsequent hydrogenation of the latter. The particular inventive feature of this process is that the aldol reaction is carried out using an aqueous formaldehyde solution having a formic acid content of <150 ppm and preferably <100 ppm. In this way of carrying out the process, the formation of by-products can advantageously be prevented in a targeted manner and the yield of the desired polymethylol compound can thereby be increased.

Abstract: Process for the catalytic hydrogenation of methylolalkanals of the general formula where R1 and R2 are each, independently of one another, a further methylol group or an alkyl group having from 1 to 22 carbon atoms or an aryl or aralkyl group having from 6 to 33 carbon atoms, in the liquid phase by means of hydrogen over a hydrogenation catalyst, wherein hydrogen is used in a molar ratio to methylolalkanal of greater than 1.

Abstract: A process is provided for the preparation of polymethylol compounds of formula (I): (HOCH2)2—C—(R)2 , ??(I) in which the radicals R independently of one another are each a further methylol group, an alkyl group having from 1 to 22 C atoms or an aryl or aralkyl group having from 6 to 22 C atoms, by (a) condensing aldehydes having from 2 to 24 C atoms with formaldehyde in an aldol reaction using tertiary amines as a catalyst to give alkanals of formula (II): in which the radicals R independently of one another are each as defined above, (b) then separating, by distillation, the reaction mixture obtained into a bottom product comprising predominantly the compounds of formula II and a low-boiling stream consisting of unconverted or partially converted starting materials, and (c) hydrogenating the distillation bottom, wherein the aldol reaction is carried out with an aqueous formaldehyde solution having a methanol content of 0.35 to 0.

Abstract: Process for the catalytic hydrogenation of methylolalkanals of the general formula where R1 and R2 are each, independently of one another, a further methylol group or an alkyl group having from 1 to 22 carbon atoms or an aryl or aralkyl group having from 6 to 33 carbon atoms, in the liquid phase by means of hydrogen over a hydrogenation catalyst, wherein hydrogen is used in a molar ratio to methylolalkanal of greater than 1.