Design and synthesis of novel chiral pyrrolidine-based diamines with C2-symmetry

Novel chiral pyrrolidine-based diamines with C2-symmetry 2, 3 and their related compounds 4 – 8 were designed and synthesized in optically pure forms. Both (+)- and (−)-2 were prepared from optical active ditosylane 9. 3 was prepared from 3,5-dimethylbenzaldehyde through optical resolution and its absolute stereochemistry was correlated with 2,3-dimethylsuccinate 27. 4 was prepared from (−)-diol 28. 5 – 8 were prepared from 9 and 11.