One-Pot Synthesis of Novel Cyclopentene-Fused Octahydropyridoquinolines and Octahydrophenanthrolines

New cyclopentene-fused octahydropyridoquinolines and octahydrophenanthrolines were prepared by a stereoselective three-component cyclocondensation of benzene-1,4-diamine, cyclopenta-1,3-diene, and an aromatic aldehyde. Single-crystal X-ray diffraction data provided evidence for the formation of cyclopentene-fused octahydropyridoquinolines and octahydrophenanthrolines with a syn -planar arrangement of the cyclopentene rings. The cyclocondensation of benzene-1,4-diamine, cyclopenta-1,3-diene, and formaldehyde gave new type of polycyclic compound containing four cyclopentene moieties oriented in a mutually antiplanar manner.