Total Synthesis Of Malyngamide J And Tandem Ring Expanding/Michael Reaction Of Cyclohexane Epoxides

This thesis was concerned with the studies on the asymmetric total synthesis of malyngamide J. Suzuki-Miyaura coupling, glycosidation and Stille coupling reaction were the key reactions involved in the total synthesis of malyngamide J, The stereoselective total synthesis of malyngamide J and 1"’-epi-malyngamide J had been achieved via a concise, convergent route using D-(-)-quinic acid as chiral building blocks. The tandem ring expanding Michael addition reaction of cyclohexane epoxides under base conditions was founded during the experimental. It mainly consists of the following four parts:In chapter 1, the principles for the formation of glycoside bond were discussed. Developments, from glycosyl donors and activation conditions, protecting groups and intramolecular glycoside-bond formation led to significant advances in oligosaccharide and glycoconjugate synthesis.have been compiled and evaluated.In chapter 2, total synthesis of malyngamide J was introduced. Firstly, the the recent progress in research of marine natural product-malyngamides was summarized and bring forward a new strategy which could synthesis of this kind of molecules. A series of such molecules through a common intermediate were synthesized. a-Iodoenone was prepared from D-(-)-quinic acid according to a literature procedure. The xylosyl donor was obtained from L-(-)-xylose via a functional transformation. The Suzuki-Miyaura coupling, Stille cross-coupling reaction and glycosidation were used as key reactions in the synthesis of malyngamides J and 1"’-epi-malyngamide J.The last was mainly about the tandem ring expanding/Michael reaction of cyclohexane epoxides under base conditions. Cyclohexane epoxides were found to be very sensitive to base, different cyclohexane epoxides could undergo different ring opening, ring expanding and tandem ring expanding/Michael reaction of cyclohexane epoxides.