本論文共分為兩個部分,第一部分是天然物ottelione A和B之全合成研究。以(-)-quinic acid(111)為起始物經數步反應獲得化合物(-)-92後,經由1,4-加成及碘化反應得到α-碘基酮化合物(-)-94並且利用了分子內自由基環化反應為關鍵步驟建構順式-六,五-駢環,經過二十三個步驟完成(+)-ottelione A(1)的全合成,總產率為1.7%。最後將(+)-ottelione A(1)於鹼性性條件進行反應就可以得到 (-)-ottelione B(2)。 本論文第二部分是天然物ingenol之合成研究。以(+)-3-carene (20)為起始物經數步反應獲得化合物90後,經由1,4-加成及碘化反應得到具有烯丙基苯硫基支鏈的α-碘基酮化合物172,以自由基環化反應為關鍵步驟建立ingenol的A、C環部分,更避免在環化時產生開三員環的副產物之產生。
The thesis consists of two parts. The first part reports our efforts in the total synthesis of otteliones A and B. Our synthesis began with compound (-)-92 prepared from commercially available (-)-quinic acid (111). 1,4-Addition of enone (-)-92 followed by iodination afforded α-iodoketone (-)-94. The key step is the radical cyclization of α-iodoketone to construct cis-hydrindanone skeleton. We achieved total syntheses of (+)-otteliones A (1) in 23 steps and 1.7% overall yield. Finally we converted (+)-ottelione A to (-)-ottelione B in basic condition. The second part reports the synthesis study of ingenol. Our synthesis began with compound 90 prepared from commercially available (+)-3-carene (20). 1,4-Addition of enone 90 followed by iodination furnished α-iodoketone 172 bearing an allyl phenyl sulfide side chain. The key step is the radical cyclization of α-iodoketone to construct the A and C rings of ingenol and prevent ring opening of the cyclopropane ring during the cyclization.