Process for the hydroformylation of diisobutene with preceding distillation

A process for the hydroformylation of diisobutenes, wherein the process comprises:

• (a) supplying a diisobutene stream, comprising 2,4,4-trimethylpent-2-ene and 2,4,4-trimethylpent-1-ene, to at least one distillation column and separating the diisobutene stream into at least one overhead stream that is enriched with 2,4,4-trimethylpent-1-ene compared to the diisobutene stream used and contains more than 85% by weight of 2,4,4-trimethylpent-1-ene, and a residual stream depleted in 2,4,4-trimethylpent-1-ene compared to the diisobutene stream used;
• (b) supplying the at least one overhead stream to the hydroformylation whereby 2,4,4-trimethylpent-2-ene and 2,4,4-trimethylpent-1-ene are in a reaction zone reacted with synthesis gas in the presence of a homogeneous catalyst system, comprising at least Co or Rh and optionally a phosphorus-containing ligand to obtain a liquid product mixture, the liquid product mixture comprising at least one aldehyde formed by the hydroformylation, the homogeneous catalyst system and unreacted 2,4,4-trimethylpent-2-ene and 2,4,4-trimethylpent-1-ene;
• (c) removing the homogeneous catalyst system from the liquid product mixture to obtain a crude product mixture, comprising the at least one aldehyde formed by the hydroformylation and unreacted 2,4,4-trimethylpent-2-ene and 2,4,4-trimethylpent-1-ene;
• (d) distillative processing of the crude product mixture in at least one distillation column to remove unreacted 2,4,4-trimethylpent-2-ene and unreacted 2,4,4-trimethylpent-1-ene, wherein the unreacted 2,4,4-trimethylpent-2-ene and 2,4,4-trimethylpent-1-ene are removed and recycled to the hydroformylation in (b).