153. Chiral toluene-2,α-sultam auxiliaries: Preparation and structure of enantiomerically pure (2R)- and (S)-ethyl-2,1’-sultam
     Oppolzer, W.; Wills, M.; Starkemann, C.; Bernardinelli, G.
     Tetrahedron Lett. 1990, 31, 4117-4120

Crystalline sultams (R)-2 or (S)-2 were selectively prepared from prochiral saccharine (3) in two steps (53% overall yield) via Ru-(R)-BINAP- or Ru-(S)-BINAP catalyzed asymmetric hydrogenation of imine 4. Alternatively, pure (R)-2 was synthesized (37% overall yield) from (R)-α-phenethylamine in 4–5 steps involving the ortho-sulfination 6 → 7 and the highly diastereoselective cyclization of sulfinic acid 7 to the sulfinamide 8. X-ray diffraction analyses of sulfinamide 8 and sultam (R)-2 are presented.

DOI : 10.1016/S0040-4039(00)97557-9 

archive ouverte unige:152794