ChemInform Abstract: OPTICAL ACTIVATION OF 2‐PHENYLPROPIONALDEHYDE VIA SOME 2‐SUBSTITUTED PYRROLIDINE ENAMINES

Optical activation of 2-phenylpropionaldehyde (PPA) via enamines using L-proline derivatives as amine components was studied. S(+)-PPA was obtained when R(−)-2-methylpyrrolidine and S(−)-2-ethoxycarbonylpyrrolidine were used, while R(−)-PPA was obtained when S(−)-prolinamide, N-(L-prolyl)pyrrolidine, N-(L-prolyl)piperidine, S(+)-2-(1-pyrrolidinylmethyl)pyrrolidine, and S(+)-2-(piperidinomethyl)pyrrolidine were used. This suggests that there are two mechanisms for optical activation.