The Studies On Ring Expansion Of Polysubstituted Cyclopropanes

Due to the special geometry of the polysubstituted cyclopropane, it is an important class of organic synthetic intermediates. Therefore, polysubstituted cyclopropane, as the raw material, can be more rich variety of heterocyclic compounds, synthesis of natural products and pharmaceutical intermediates. The intramolecular ring-opening cyclizations of cyclopropanes serve as powerful tools in synthesis and foreseeable applications in medicinal chemistry, chemical biology, materials science and pharmaceutical industry. As a part of our continuous research toward the development of new cyclic compounds and structural diversities, using the polysubstituted cyclopropane as essential building blocks, we report our efforts towards the synthesis of indolizine derivatives,1,3-cyclopentadiene compounds, and fully substituted benzene compounds.Part 1:Indolizine derivatives were synthesized through one-pot reaction with polysubstituted cyclopropane, pyridine,4-dimethylaminopyridine, quinoline or isoquinoline as building blocks. We synthesized twenty-one new products by optimising the reaction conditions. All target compounds were characterized by NMR, IR, and LC-MS spectroscopy. The single crystal structures of three polysubstituted indolizines were confirmed by X-ray diffraction method.Part 2:Substituted 1,3-cyclopentadiene compounds were synthesized through one-pot reaction with polysubstituted cyclopropane, substituted β-nitrostyrene as building blocks. After optimising the reaction conditions, we synthesized twenty-two new products. All target compounds were characterized by NMR, IR, and LC-MS spectroscopy. The single crystal structure of one product was confirmed by X-ray diffraction method.Part 3:Using two molecules of polysubstituted cyclopropanes as building blocks, fully substituted benzene compounds were synthesized via one-pot reaction. All products were characterized by NMR, IR, and LC-MS spectroscopy. The single crystal structure of one product was confirmed by X-ray diffraction method.