Thirteen years after thier first observations with the pyridinium salt
photocyclization process, Mariano and co-workers returned to this area and have
subsequently reported on several occasions their investigations into the potential
synthetic power of a tandem sequences involving:
(1) photoinduced cyclization of pyridinium cations
(2) stereocontrolled nucleophile addition to produce bicyclic aziridines, and
(3) stereocontrolled nucleophilic cleavage of the bicyclic aziridine to produce
highly functionalized aminocyclopentenes.