Asymmetric hydrogenation of isophorone in the presence of (S)-proline: Revival of a 20 years old reaction

The asymmetric hydrogenation of isophorone in the presence of (S)-proline was reinvestigated in the light of recent papers of Torok et al. and Lambert et al. Beside kinetic resolution of trimethyl cyclohexanone with (S)-proline, the chemo- and diastereoselective hydrogenation of isophorone is the source of optically active trimethyl cyclohexanone, which was proved by reaction rate, GC, GC–MS measurements and preparative experiments.