Unexpected change of the sense of the enantioselective hydrogenation of ethyl pyruvate catalyzed by a Pt-alumina-cinchona alkaloid system.
In the enantioselective hydrogenation of ethyl pyruvate (EtPy) over beta-isocinchonine (beta-ICN) modified Pt-alumina catalysts, the major enantiomer was (R)-ethyl lactate ((R)-EtLt (ee 50%)) in toluene, while in AcOH (S)-EtLt (ee 60%) was formed; the (R) configuration is opposite to what is expected from the absolute configuration of the cinchonine backbone.
Organic Catalysis Research Group of the Hungarian Academy of Sciences, University of Szeged, Dóm tér 8 H-6720, Hungary. bartok@chem.u-szeged.hu
M
M
Bartók
M
M
Sutyinszki
K
K
Felföldi
Gy
G
Szöllósi