The Synthesis Of Natural Products Research Parnafungins Class

This thesis focuses on the synthesis of isoxazolidinone ring system of Parnafungins A and B. which is divied into four parts:Chapterl. Literature ReviewThis chapter introduces advances of studies on antifungal natural compounds and the development process of Parnafungins. We summarized and concluded synthesis approachs of natural product Parnafungins with predecessors.Chapter2. Proposal and design of this topicBecause of their unique structure and significant pharmacological activity, more and more chemists were attracted in this subject. But there was not reported for the total synthesis approach of Parnafungins until now, so it is necessary to develop an effective total synthetic route for Parnafungins. This chapter introduces the retro synthesis of Parnafungins.Chapter3. Results and discussionThis chapter summarizes a series of problems in the experiment and the solutions, which lay the foundation for the follow-up work.Chapter4. Experimental sectionIn this thesis,2-amino-3-bromobenzoic acid was synthesized in high yield starting from commercially available2-bromoaniline. Then contains two different protection of the acyl chloride was synthesized through the selective protection and acylation reaction from commercially available3,5-dihydroxybenzoic acid, which then underwent amidation, cyclization reaction to give the key tricycle. This work is still ongoing. After11steps we got the key intermediate—compound22in the total yield of17.1%.