Studies in asymmetric synthesis: Diastereoselective manipulations of conformationally anchored heterocycles and carbocycles.

Abstract

The research, to be presented in two chapters discusses the development of new methods in asymmetric synthesis which may be applicable to the total synthesis of natural products. Chapter 1. We have developed the methodology to functionalize heterocycles such as tetrahydropyran and tetrahydrofuran using intermolecular diastereoselective radical trapping reactions. This method was also extended to prepare bicyclic acetals with three chiral centers using intramolecular radical reactions. The stereocontrol in both intermolecular and intramolecular reactions was studied. This methodology may be developed further to synthesize deoxygenated and substituted carbohydrates. Chapter 2. The highly functionalized eight membered carbocycle is the basic structural unit of many natural products of biological interest. The methodology developed and presented in this chapter utilizes chiral cyclopropyl ketals of eight member carbocycle and introduces functionalities on the eight membered ring with good stereocontrol. This methodology has direct application in the synthesis of many natural products containing functionalized eight member carbocycles.