Heterocyclic compounds Ring formation (Chemistry) 4 Organic chemistry 3 Aromatic compounds 2 Chemistry 2 Dissertations, Academic (Ph.D) 2 Thesis (Ph.D)-Chemistry 2 Alicyclic compounds 1 Aliphatic compounds 1 Bioactive compounds 1 Carbocyclic compounds 1 Carbohydrates 1 Chemische Synthese 1 Chemistry, Organic 1 Chemistry, organic 1 Diels-Alder reaction 1 Dipolar cycloaddition 1 Heterocyclic Compounds 1 Heterocyclic chemistry 1 Heterocyclic compounds-Synthesis 1 Heterocyclische Verbindungen 1 Heterogeneous catalysis 1 Hydrocarbuns 1 Ketenes 1 Mass spectrometry 1 Natural products 1 Naturstoff 1 Nitrogen compounds 1 Nuclear magnetic resonance spectroscopy 1 Organic Chemistry 1