Strategies Toward the Total Synthesis of (+)-Waihoensene

In this thesis, we will be presenting three different synthetic strategies we attempted to achievethe total synthesis of waihoensene. 18 In chapter 1, we describe our attempts at an oxidative coupling approach towards waihoensene which used a hypervalent iodine mediated oxidative coupling reaction as the key step for constructing the tetraquinane ring structure followed by a ring expansion to get the carbon ring framework of the natural product. In chapter 2, we describe our attempts toward a Rhodium catalyzed C-H activation strategy to the natural product. Here, we attempted a SmI2 mediated reductive coupling to construct a bicyclic structure followed by a C-H activation reaction of a diazo compound to generate the tetraquinane structure. In chapter 3, we describe our final and successful attempt toward the natural product. In this route, we employ a Pauson-Khand reaction to construct the carbon ring framework of the natural product and use quaternary centers as a guide to set the correct stereochemistry at all the chiral centers of the molecule. Before our synthesis began, there were no reported synthesis of waihoensene and only Moore's synthesis of the waihoensene ring system was published. During our synthetic attempts, Lee's first total synthesis was published. Yang's total synthesis and Tong and Wu's model study was published while our manuscript was under review.