Studies On The Biomimetic Synthesis Of Marine Natural Product Ningalin A

The thesis aims at studies on biomimetic synthesis of marine natural product Ningalin A and the methods of synthesis pyrrole derivatives. It mainly consists of the following two parts.Chapter1:Biomimetic Synthesis of marine natural product Ningalin ANingalin A is the simplest member of a newly described family of marine natural pr oducts isolated by Fenical (1997) from an ascidian of the genus Didemnum collected in Western Australia near Ningaloo Reef, which is a highly unsaturated (15units of unsaturation) aromatic compound. Only five proton resonances were observed in the1H NMR. The special structure of Ningalin A, attracted the attention of synthetic organic chemists. Reported that Ningalin A’s biosynthetic precursor compounds is DOPA, but no related biological or biomimetic synthesis were reported. Through literature research, we hypothesized that the biosynthstic pathway of Ningalin A, and designed biomimetic synthesis route of Ningalin A. our group designed to uitiize commercial available L-DOPA as starting marerial. The carboxylic group and the phenol hydroxyl group was protected by methyl group, afforded3,4-dimehyoxyphen ylalanine methyl ester. The resulted compound was treated with Cu(OAc)2without any seperation, through dehydrogenation, deamination and cycliztion reaction got key pyrrole intermediate. With this key intermidiate in hand, through oxidation cyclization reaction, we persue a biomimetic synthesis approach to synthesis Nigalin A.Chapter2:study on the methods of synthesis pyrrole derivatives (review)Pyrrole and its derivatives, is one of the most important ptentatonic heterocyclic compounds, which widely present in various natural products and drugs. Many of them have also been used in material science, especially muti-polypyrrole which play an important role in supermolecular chemistry. Since pyrrole compounds have good biological activity and drug activity, the study of synthesis and applications of these compounds have received the research scientists’widespread concern and attention. This chapter provides an overview of pyrrole and its derivatives’classical synthetic methods and the new synthetic methods developed in recent years.