Process for preparing the dialdehyde of vinylcyclohexene

Process comprising the process steps of:

• a) initially charging vinylcyclohexene;
• b) adding a compound of formula (I):
• where R1, R2, R3, R4, R5, R6, R7, R8 are selected from:
• —H, —(C1-C12)-alkyl, -Ph;
• c) adding a Pt compound capable of forming a complex;
• d) adding an iodine compound;
• e) feeding in CO and H2;
• f) heating the reaction mixture from steps a) to e), to convert the vinylcyclohexene to the dialdehyde.