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-(omega-aminoalkyl)pyrrolidines, whereas these substrates react with H-2 or cyclohexene in the presence of catalytic amounts of Pd/C to give benzyl- or benzylidene-substituted bicyclic amidines, respectively.