Abstract: The invention relates to a process for obtaining a pure aliphatic dialdehyde monoacetal by reaction of the corresponding aliphatic dialdehyde or a precursor of the corresponding aliphatic dialdehyde with one or more aliphatic mono- or polyhydric alcohols while distillatively removing water to obtain a reaction mixture which is separated distillatively, which comprises carrying out the distillative separation continuously in a dividing wall column to obtain pure aliphatic dialdehyde monoacetal as a sidestream from the dividing wall column, or in two distillation columns to obtain crude aliphatic dialdehyde monoacetal as a sidestream in the first distillation column, feed the crude aliphatic dialdehyde monoacetal to the second distillation column and obtain pure aliphatic dialdehyde monoacetal as the sidestream from the second distillation column.

Abstract: A process for the recovery of a Lewis acid from a reaction mixture (I) which has been obtained in the hydrocyanation of an olefinically unsaturated compound to a nitrile which has a miscibility gap with water under certain pressure and temperature conditions, in the presence of a catalyst system comprising a Lewis acid and a complex compound.

Abstract: A process for the removal of water from a mixture comprising water and zinc chloride, which comprises adding to said mixture comprising water and zinc chloride an aprotic, polar diluent whose boiling point in the case where an azeotrope is not formed between said diluent and water under the pressure conditions of the distillation mentioned below is higher than the boiling point of water and which is in liquid form at this boiling point of water or which forms an azeotrope or heteroazeotrope with water under the pressure and temperature conditions of the distillation mentioned below, and distilling the mixture comprising water, zinc chloride and the diluent with removal of water or said azeotrope or said heteroazeotrope from this mixture, giving an anhydrous mixture comprising zinc chloride and said diluent.

Abstract: The invention relates to phosphinites I of formulae (1) or (2), in which R1, R2, R5, R6, R7, R8, R9 independently represent hydrogen, an alkyl or alkylene group having 1 to 8 carbon atoms or an alkoxy group having 1 to 8 carbon atoms; R3 is H or methyl; R4 is i-propyl or t-butyl; X is F, Cl or CF3 and n is 1 or 2.

Abstract: Phosphinites I of the formula 1, 2 or 3 where R1, R2, R4 are each, independently of one another, hydrogen, an alkyl or alkylene group having from 1 to 8 carbon atoms or an alkoxy group having from 1 to 8 carbon atoms, with the proviso that at least one of the groups R1, R2, R4 is not H, R3 is H or methyl X is F, Cl or CF3 n is 0, 1 or 2 can be used as catalysts.

Abstract: Phosphonites I of the formula 1 or 2 1

Abstract: A catalyst system containing a) Ni (0), b) 4-10 mol per mol Ni (0) according to a) a compound (I) of formula P (X1R1) (X2R2) (X3R3) (I) wherein X1, X2, X3 independently represent oxygen or a single bond R1, R2, R3 represent independently, the same or different organic radicals, and c) 1-4 mol per mol Ni (0) according to a) a compound (II) of formula (II) wherein X11, X12, X13, X21, X22, X23 independently oxygen or a single bond, R11, R12 independently represent the same or different individual or bridged organic radicals, R21, R22 independently represent the same or different, individual or bridged organic radicals, Y represents a bridge group.