I. Studies toward the formal synthesis of (+)-aldosterone. II. Type 2 intramolecular hetero Diels-Alder reaction and the discovery of a novel tandem hetero Diels-Alder reaction

This dissertation focuses on the type 2 intramolecular Diels-Alder reaction and its application in organic synthesis. Chapter 1 introduces the intermolecular Diels-Alder reaction and discusses the nuances of the reaction. The type 1 intramolecular Diels-Alder reaction is discussed briefly. An overview of the type 2 intramolecular Diels-Alder reaction is presented. Chapter 2 discusses the synthetic efforts towards the formal synthesis of (+)-aldosterone using the type 2 intramolecular Diels-Alder reaction as the key step in controlling the regio-, stereo-, and π-facial selectivity of the cycloaddition reaction. We used the chiral disposable tether methodology to reverse the π-facial selectivity of the type 2 intramolecular Diels-Alder reaction relative to the system containing an achiral tether. This accomplishment allowed for the enantioselective synthesis of the core of the steroid (+)-aldosterone.; Chapter 3 describes our efforts to expand the type 2 intramolecular Diels-Alder reaction to include heteroatoms. Specifically, the synthesis of bridgehead dihydropyrans using 2-activated-1-oxabutadiene cycloaddition precursors was explored. The utility of the dihydropyran products as precursors to medium ring ethers is discussed. In these studies, a novel tandem hetero Diels-Alder reaction was discovered and the finding are presented in chapter 4.; Chapter 5 describes the development of chiral silicon auxiliaries for the type 2 intramolecular Diels-Alder reaction. The purpose of using chiral silicon auxiliaries is to have them control the π-facial selectivity in the cycloaddition reaction in order to enantioselectively synthesize cyclohexenyl systems.