NEW CONVENIENT, ENANTIOSPECIFIC SYNTHESIS OF (S,S)-2,2'-BIPYRROLIDINE AND (R,R)-2,2'-BIPYRROLIDINE DERIVATIVES

An enantiomeric pair of (S,S)- and (R,R)-bipyrrolidine derivatives has been prepared from D-and L-tartaric acids or D-mannitol as optically active starting materials. Taking advantage of the C-2-symmetric nature of these chiral sources, the synthetic sequence has been established by using efficient side chain elongation, stereospecific conversion of a vicinal diol into a diazido group via S(N)2 inversion, and pyrrolidine ring formation via intramolecular substitution as the key steps.