Selective Reduction and Dehydrogenation of 6-Benzylideneoctahydropyrrolo[1,2-a]Pyrimidines and 5-Benzylidenehexahydropyrrolo[1,2-a]Imidazoles as New Approaches to N-(ω-Aminoalkyl)Pyrrolidines and Bicyclic Amidines

Sodium borohydride reduction of 6-benzylideneoctahydropyrrolo[1,2-a]pyrimidines and 5-benzylidenehexahydropyrrolo[1,2-a]imidazoles affords N-(w-aminoalkyl)pyrrolidines, whereas these substrates react with H₂ or cyclohexene in the presence of catalytic amounts of Pd/C to give benzyl- or benzylidene-substituted bicyclic amidines, respectively.