Total Synthesis Of Diospongin A And Yashabushidiol A

The dissertation is composed of two parts:Part 1. A review on the synthesis of 1,7-diarylheptanoids nature products Diospongins and YashabushidiolRecently, there is a new family of 1,7-diarylheptanoids naming Diospongins including diospongin A and B, which exhibit promising anti-osteoporotic activity. Due to the biological activities of diospongins, many chemists have been attracted, followed with several synthesis routes reported.In 1986, another diarylheptanoids named yashabushidiol A and B has been isolated. Findings on the characteristic aroma and potent cytotoxic activities spured chemists to synthesis and extend to the evaluation of the cytotoxic activities.In this chapter, we would like to give a concise summary on the synthesis of these two 1,7-diarylheptanoids.Part 2. Studies on the synthesis of Diospongin A and Yashabushidiol AFirstly, (2SR,4RS)-pentane-1,2,4,5-tetraol has been smoothly achieved from D-ribose via five steps. Then, based on the symmetry of starting material in accordance with yashabushidiol A, by the twofold extension of carbon chain and through the modification and transformation of functional groups, we have achieved the synthesis of Yashabushidiol A. The attractiveness of this route is also evident by proceeding the Lewis Acids-induced unsymmetric cyclization, constructing the final relative configuration of Diospongin A.In addition, inspired by the work of constructing the chiral tetrahydropyran by A. B. Smith, we tried to utilise the Petasis-Ferrier rearrangement as the key step to accomplish the total synthesis of (-)-Diospongin A.