Mitomycin Synthetic Studies: Stereocontrolled and Convergent Synthesis of a Fully Elaborated Aziridinomitosane

Full details of a stereocontrolled and convergent synthetic route to 9a-desmethoxymitomycin A (1)
are reported. The target molecule possesses the parent tetrahydropyrrolo[1,2-a]indole ring system
characteristic of the mitomycin family of antitumor agents. The synthesis was based on the
diastereocontrolled addition of a fully elaborated cinnamylstannane to a pyrrolidine-based
N-acyliminium ion as the key convergent step, which resulted in the installation of the C9 and
C9a stereogenic centers.