Convenient Formation of Six- to Nine-Membered Carbocyclic Rings by 2-Pyridyl Radical Cyclization: A Generalized Synthesis of Pyridine-Fused Linear Tricyclic Systems - Maiti, Sarbendu; Drew, Michael G B; Mukhopadhyay, Ranjan; Achari, Basudeb; Banerjee, Asish Kr (Synthesis, 2005)