Abstract A new class of endocyclic enamines, 1, 6-disubstituted 1, 2, 3, 4, 5, 6, 7, 8- octahydro-1, 6-naphthiridines, was synthesized from 4-piperidone imines by successive subjecting the latter to lithiation with lithium diethylamide, to alkylation with 1-bromo-3- chloropropane, and to intramolecular cyclization. All stages were carried out as a unique process without isolation of the intermediate compounds. A thorough optimization of the ...
