The enantioselective hydrogenation of ethyl pyruvate to (R)- and (S)-ethyl lactate over Pt/Al2O3 catalyst was investigated using epiquinine (42% ee) and cpiquinidine (22% ee) as modifiers and the results were compared with those found for quinine (85% ee) and quinidine (81% ee). The experimental results show that the sense of enantioselection is determined by the conformation of the entire alkaloid, and the structure of the intermediate is a 1:1 complex of the pyruvate and the 'anti open' conformer of the cinchona alkaloid.
- Epicinchona alkaloids
- Ethyl pyruvate
ASJC Scopus subject areas
- Physical and Theoretical Chemistry