Diphosphites based on cis-butene-1,4-diol

1. A compound having structure (I) or (II):

where R 1 , R 2 , R 3 , R 4 , R 5 , R 6 , R 7 and R 8 are selected from: —H, —(C 1 -C 12 ) alkyl or —O—(C 1 -C 12 ) alkyl,

and the radicals R 1 , R 2 , R 3 , R 4 , R 5 , R 6 , R 7 and R 8 are not all simultaneously — t Bu.

2. The compound according to claim 1 ,

where R 1 , R 4 , R 5 and R 8 are selected from: —H or —(C 1 -C 12 ) alkyl.

3. The compound according to claim 1 ,

where the radicals R 1 , R 4 , R 5 and R 8 are not all simultaneously — t Bu.

4. The compound according to claim 1 ,

where the radicals R 1 , R 4 , R 5 and R 8 are not — t Bu.

5. The compound according to claim 1 ,

where at least one of the radicals R 1 , R 4 , R 5 and R 8 is —H.

6. The compound according to claim 1 ,

where R 2 , R 3 , R 6 and R 7 are selected from: —H or —O—(C 1 -C 12 ) alkyl.

7. The compound according to claim 1 ,

where at least one of the radicals R 2 , R 3 , R 6 and R 7 is —H.

8. The compound according to claim 1 ,

where the compound has the structure (I).

9. The compound according to claim 1 ,

where the compound has the structure (I):

10. The compound according to claim 1 ,

where the compound has the structure (II).

11. The compound according to claim 1 ,

where the compound has the structure (2):

12. A ligand-metal complex comprising the compound according to claim 1 and a metal selected from: Rh. Ru, Co or Ir.

13. A process comprising the process steps of:

a) initially charging an olefin,

b) adding a compound according to claim 1 and a substance containing a metal selected from: Rh, Ru, Co or Ir,

c) feeding in H 2 and CO, and

d) heating the reaction mixture from steps a) to c), with conversion of the olefin to an aldehyde.