US 7,557,240 B2
Method for the production of optically active alkyl succinic acid monoalkyl esters
Frank Hettche, Weinheim (Germany); Christoph Jäkel, Limburgerhof (Germany); Marko Friedrich, Lorsch (Germany); and Rocco Paciello, Bad Dürkheim (Germany)
Assigned to BASF Aktiengesellschaft, (Germany)
Appl. No. 11/571,725
PCT Filed Jul. 06, 2005, PCT No. PCT/EP2005/007289
§ 371(c)(1), (2), (4) Date Jan. 05, 2007,
PCT Pub. No. WO2006/002999, PCT Pub. Date Jan. 12, 2006.
Claims priority of application No. 10 2004 032 968 (DE), filed on Jul. 07, 2004; and application No. 10 2005 007 750 (DE), filed on Feb. 18, 2005.
Prior Publication US 2008/0058547 A1, Mar. 06, 2008
Int. Cl. C07C 69/34 (2006.01)
U.S. Cl. 560—190 12 Claims
 
1. A process for preparing optically active alkylsuccinic acid monoalkyl esters of the formula (I)

OG Complex Work Unit Drawing
where D and E are independently of one another H, C1-C10 alkyl,
R is C1-C10 alkyl, aryl or alkylaryl,
which comprises enantioselective hydrogenating a compound of the formula (II)

OG Complex Work Unit Drawing
where D, E and R have the abovementioned meanings,in the presence of a catalyst that has Rh, Ru or Ir as a metal atom which includes a phospholane ligand of the formula (L)

OG Complex Work Unit Drawing
where:
R1 and R2 are independently of one another C1-C6 alkyl, aryl, alkylaryl,
R1 is additionally hydrogen,
A is either R1 or

OG Complex Work Unit Drawing
with B=a linker with 1-5 C atoms between the two P atoms or Cp-Fe-Cp.