1. The tautomerism of heterocycles: Substituent tautomerism of six-membered ring heterocycles (B. Stanovnik, M. Tišler).
2. Homologation of heterocycles by a sequential reductive opening lithiation– electrophylic substitution–cyclization (M. Yus, F. Foubelo).
3. Coenzyme 5,10-methylene and methenyltetrahydrofolate models in organic synthesis (K. Singh, H. Singh).
4. Advances in the chemistry of naphthyridines (V.P. Litvinov).