Method of obtaining aldehydees by hydroformation with modification of ligands by acetalization

FIELD: chemistry. SUBSTANCE: method comprises the following steps: - autoclaving ethanol (A), rhodium dicarbonyl rhodium (acac) acetylacetonate (CO) 2 (B), with a B:A ratio of 1:6000 to 1:10000 in weight fractions, a ligand containing an aromatic phosphine residue and at least two hydroxyl groups (C) at a B:B ratio of 1:1 to 5:1 in mole fractions, a linear olefin of the C 4 -C 20 , (D) at a ratio of "D:B" from 500:1 to 5000:1 in mole fractions and cation exchanger in acid form (D), taken in 10-20-fold excess relative to the ligand (B); - autoclaving of synthesis gas pressure (CO/H 2 =1:1) 0.1-10 MPa, heating the mixture to 30-120°C, the synthesis being carried out with stirring with a magnetic stirrer at 500-1000 rpm for 3-10 hours to form an aldehyde and a rhodium catalytic complex with a bulky ligand; - separating the cation exchanger by filtration and separating the rhodium catalytic complex with the bulky ligand by membrane nanofiltration from a mixture of aldehyde with a solvent, followed by evaporation of the solvent. Also, the invention relates to a process of separating rhodium complex of a ligand (C) of the rhodium complex catalyst a bulky ligand obtained in the hydroformylation process, consisting in expansion volume ligand mineral acids in the weight ratio acid: ligand = 1:19. EFFECT: bulk ligand in the hydroformylation process allows for efficient separation of the catalyst complex from the product - aldehyde. 5 cl, 3 ex