3. 4 Electrocyclic processes in heterocyclic ring synthesis 61 3. 5 Nitrenes in heterocyclic ring synthesis 62 References for chapter 3 63 4 Typical reactivity of pyridines, quinolines and isoquinolines 64 5 Pyridines: reactions and synthesis 72 5. 1 Reactions with electrophilic reagents 73 5. 2 Reactions with oxidising agents 79 5. 3 Reactions with nucleophilic reagents 80 5. 4 Reactions with bases 82 5. 5 Reactions of C-metallated pyridines 83 5. 6 Reactions with radical reagents 85 5. 7 Reactions with reducing agents 86 5. 8 Electrocyclic reactions (ground state) 87 5. 9 Photochemical reactions 88 5. 10 Oxy-and aminopyridines 89 5. 11 Alkylpyridines 94 5. 12 Pyridine aldehydes, ketones, carboxylic acids and esters 95 5. 13 Quatemary pyridinium salts 95 5. 14 Pyridine N -oxides 10 1 5. 15 Synthesis of pyridines 104 References for chapter 5 111 Exercises for chapter 5 118 6 Quinolines and isoquinolines: reactions and synthesis 120 6. 1 Reactions with electrophilic reagents 121 6. 2 Reactions with oxidising agents 123 6. 3 Reactions with nucleophilic reagents 123 6. 4 Reactions with bases 125 6. 5 Reactions of C-metallated quinolines and isoquinolines 126 6. 6 Reactions with radical reagents 126 6. 7 Reactions with reducing agents 126 6. 8 Electrocyclic reactions (ground state) 127 6. 9 Photochemical reactions 128 6. 10 Oxyquinolines and -isoquinolines 128 6. 11 Aminoquinolines and -isoquinolines 130 6. 12 Alkylquinolines and -isoquinolines 130 6.