| abstract |
A hydroformylation process for producing aldehydes, which comprises reacting an olefinic compound with carbon monoxide and hydrogen in the presence of a compound of an element selected from Groups 8 to 10 of the Periodic Table (hereinafter referred to as "Group VIII metal"); Bisphosphite compound of the following formula (A) is carried out: wherein -Ar-Ar- is a by any of the following formulas (AI) specified by (A-III) Bisarylengruppe, and each of Z 1 to Z 4 is an aromatic or heteroaromatic C 4 - 20 group, which may have a substituent wherein each of the substituents on carbon atoms of an aromatic ring adjacent to the oxygen atom bonded carbon atom in each of Z 1 to Z 4 is a C O-2 group, and wherein each of the pairs Z 1 and Z 2 and Z 3 and Z 4 not bound together, |