Abstract
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.