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Synthesis of chemical constituents from the Selaginellaceae family
Mulenga, Mutale Jane ; Rýček, Lukáš (advisor) ; Hrdina, Radim (referee)
The genus Selaginella belongs to the family Selaginellaceae. There have been about 30 selaginellins reported with possession of biological activities such as antimicrobial, cytotoxic, antioxidant, and phosphodiesterase-4 (PDE4) inhibitory properties. This master's thesis will focus on the synthesis of the natural product selaginellin T, containing the isobenzofuran- 1(3H)-one core in its structure. The first attempts to create the core were attempted via partially intramolecular [2+2+2] cyclotrimerization from the corresponding diyne connected by an ester linker and external alkyne. This strategy failed, as the formation of the stating ester was not feasible. The alternative strategy relying on [4+2] cycloaddition was evaluated, however, without any success. Finally, the isobenzofuran-1(3H)-one core was formed via [2+2+2] cyclotrimerization of the corresponding diyne connected by ether linker, leading to the corresponding 1,3-dihydroisobenzofuran, which was further oxidized to the desired lactone. The difficulties with the removal of the protecting groups were encountered at the later stage of the synthesis, and therefore, the use of alternative protecting groups is proposed. Key words: Selaginellaceae, selaginella, cyclotrimerization, metal catalysis.
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