Studies On Chemical Constituents Of A. Lancea, Coupling Reaction Catalyzed By Iodine, And Total Synthesis Of Spirotryprostatin B

This thesis work includes:the structure identification and modification of traditional Chinese medicine, skeleton construction of drug molecules, and total synthesis of natural alkaloids.The chemical constituents of Atractylodes DC were described in the first part of this dissertation. All of them were isolated by means of silica gel column chromatography, preparative thin layer chromatography and recrystallization etc. The structures of these compounds were elucidated by spectroscopic methods:UV, IR, EI-MS, HR-MS,1DNMR ('H NMR,13C NMR and DEPT),2DNMR ('H-'H COSY, HMQC. HMBC and 1H-1H NOESY) and along with comparison to authentic samples or the data from literatures. From Atractylodes DC,41 compounds were isolated, ten of them are new. Furthermore. the bioactiveties of some compounds were studied.In Chapterâ…¡, the cross-coupling reaction of copper-catalyzed aryl halides with active methylene compounds or amino acid were described. New approach to build aza-seven-membered rings and lsoquinolone skeleton were developed. Firstly, Cul-catalyzed coupling of 2-bromobenzylamines and a-amino acids and subsequent condensative cyclization (directly or mediated with DPPA) provides 1,4-benzodiazepin-3-ones in moderate yields. Using L-proline and L-valine as the starting materials enantiopure products are obtained although partial racemization occurs for other amino acids. Secondly, Cul-catalyzed coupling of 2-bromobenzylamines and a-amino acids and subsequent condensative cyclization (directly or mediated with DPPA) provides 1,4-benzodiazepin-3-ones in moderate yields. Using L-proline and L-valine as the starting materials enantiopure products are obtained although partial racemization occurs for other amino acids.In the chapter IV, we develop a construction of adjacent chiral quaternary carbon method and its application to total synthesis of Spirotryprostatin B. First of all, the coupling of precursor was synthesed from isatin and tartaric acid, and finally the best reaction conditions wetre obatained by examining different reaction conditions. The cis-and trans-coupling product could be obtained differently by controlling the reaction conditions, then this method is applied to synthes the intermediates of Spirotryprostatin B.