The Specific Synthesis of Pyridines and Oligopyridines1

A survey is given of the wide applicability of the specific syntheses of (substituted) pyridines, bi-, ter-, and oligopyridines, including those bearing condensed rings, from acalkylpyridinium salts and α,β-unsaturated ketones on treatment with ammonium acetate/ acetic acid or methanol. The complex chemical behaviour of the bi- and oligopyridines is hereby considered. 1. Syntheses of Monopyridines 1.1. Principles of the Method 1.2. Advantages of the Method 1.3. Use of 1,3-Diketones and Analogous Compounds instead of Pyridinium Salts 2. Nomenclature of Oligopyridines 3. Syntheses of Bipyridines 4. Syntheses of Terpyridines 5. Syntheses of Quaterpyridines 6. Syntheses of Quinquepyridines 7. Syntheses of Septipyridines 8. Alternative Methods for the Preparation of Oligopyridines 9. Syntheses of Pyridines bearing Condensed Rings 10. Oligopyridines as Reagents for Fe2+ and Cu1+ Ions 11. Conclusions