Studies toward the total synthesis of rac-Leuconolam, modified Julia Olefination approach to access functionalized steroidal side chains, proton-NMR Studies of Mosher-like esters, and exploring a non-enzymatic Diels Alder reaction to account for the methyl sarcophytoate core

Abstract

This Ph.D. thesis is composed of five chapters, two of which are closely related and are presented at the begining. In Chapter-I, an extensive study toward the total synthesis of a plant natural product, namely leuconolam, will be discussed. In the course of this project, two different routes have been explored, where novel synthetic methods have been developed. In particular, some of the key bond-forming events such as Ireland-Claisen rearrangement, arene-alkene coupling (via either Stille reaction or C-H bond functionlization) and allylative ring closure are highlighted.A side project that has emerged during my investigations in Chapter-I will be covered in Chapter-II. This work focuses on the synthesis of two new organometallic reagents and their utility in organopalladium mediated cross-couling reactions with various alkenyl and aryl halides. Chapter-III encompasses the studies in the area of steroid chemistry, more specifically, in chemical construction of important steroid side chains. In order for a convergent strategy, a modified Julia olefination method has been performed on a common sulfone donor with a series of uselful aldehyde acceptors. Biologically relevant derivatives of alkyl and alkoxy branched side chains have been successfully synthesized. In Chapter-IV, synthetic and spectroscopic studies in Mosher ester analysis technique will be discussed. This NMR based tool is critical in determining the absolute configuration of a stereogenic carbon center and is commonly used by organic chemists. Finally, in Chapter-V, our efforts in generating a reactive pyrylium dienophile to facilitate a Diels-Alder reaction will be outlined.