Research Of Alkene On Synthesis Of Dienyl Ketones And Ene-reaction

Stellettin F is important for its excellent biological activity, which was just isolated from sponge Stelletta tenuis Lindgren. Total synthesis of Stellettin F has not been reported by now. Carefully analyzing, we found that the side chain which was conjugated polyene actually can be constructed from the oxidative cross-coupling of olefins and cyclic structures could be obtained by polyene cyclization. Focuse on its synthesis, we developed a new method to form polyene. Meanwhile, we tried to build a suitable substrate by asymmetric catalytic ene reaction of tri-substituted olefins for the next polyene cyclization.This work is divided into four chapters:Chapter1:the development of synthesis of Stellettin F and our strategyIn this chapter we review the history of Stellettin’s separation and synthesis attempts. A new strategy for the synthesis of Stellettin F was put forward. In addition, we made a reviewed on synthsis of conjugated polyene and polyene cyclization.Chapter2:Synthesis of polyenePolyene was widely used in total synthesis as ancommon fragments of natural product. We deleoped an efficient and general method for the synthesis of conjugated dienyl ketones via palladium(Ⅱ) acetate catalyzed direct cross-coupling between simple alkenes and vinyl ketones. This method has been successfully applied for the synthesis of Vitamin A1and bornelone.Chapter3:ene reaction of tri-substituted olefinsHomoallylic alcohols are important building blocks for the synthesis of natural products and biologically active compounds. Among the many methods available, the intermolecular carbonyl-ene reaction is probably one of the best methods for the construction of C-C bond due the ease of obtaining the starting materials as well as its atom economic nature of the reaction, we have developed a simple and efficient method for the synthesis of homoallylic alcohols with high enantioselectivities and anti-diastereoselectivities via In-catalyzed intermolecular carbonyl-ene reaction. In this asymmetric carbonyl-ene reaction, the presence of a proton β-cis to the substituent of the alkene is essential for the high reactivity.Chapter4:Mukaiyama aldol reaction of isatin We applied the In-Pybox system that we developed into the Mukaiyama aldol reaction. A high enantioselective product was obtaied by addtion in the3-position of isatin. It is promisingly used in the total synthesis Convolutamydine A.