Process for preparing an aldehyde

摘要

Process for preparing an aldehyde compound by hydroformylation of an ethylenically unsaturated organic compound wherein a catalyst system is used, which catalyst system comprises rhodium and a bidentate phosphite ligand, wherein the bidentate phosphite ligand is a compound according to formula (1), wherein R<1> and R<3> are respectively an organic group which maybe the same or different and wherein R<2> is a tetravalent organic group.