Asymmetric Transformations of Proline and 2-Piperidinecarboxylic Acid via Formation of Salts with Optically Active Tartaric Acid

Article abstract of DOI:10.1246/bcsj.64.3251

The rates of racemization of optically active proline and 2-piperidinecarboxylic acid by using aldehydes as a catalyst tended to increase with a decrease in the acidity of the carboxylic acid used as solvent.Based on these results, the asymmetric transformations of DL-Pro and (RS)-Pia were carried out via formation of salts with (2R,3R)-tartaric acid to give optically pure L-Pro in over 80percent yield and (R)-Pia in 70percent yield.The asymmetric transformation of L-Pro was more successfully achieved by using (2S,3S)-tartaric acid to give optically pure D-Pro in 85percent yield based on the starting L-Pro.