Unit-I : Nomenclature of Heterocycles, Aromatic heterocycls, Unit-II : Non-atomatic Hetrocycles, Ring Synthesis, Types of Reactions, Unit-III : Small Ring Hetrocycles, Unit-IV : Mesoionic Heterocycles, Six Memered Heterocycles with One heteroatom, Unit-V : Six Membered Heterocycles with two or more heteroatoms, Heterocyclic Systems containing P, B As & Sb, Question Papers.