relation: http://d-scholarship-dev.library.pitt.edu/8937/
title: Asymmetric Alkenyl Zirconocene/Zinc Additions to Aldehydes and Synthetic Efforts Toward Pseudotrienic Acid A
creator: Jayasuriya, Nilukshi Renuka
description: The in situ hydrozirconation-transmetalation-aldehyde addition process is a convenient method for the generation of allylic alcohols. Ongoing research has focused on enhancing the enantioselectivity and substrate scope of this process and will be the focus of Chapter 1. Investigations have shown that both amino alcohols and amino thiols show moderate to high enantioselectivity. Non-linear effects were analyzed in order to gain mechanistic insight into the asymmetric addition process. Additionaly, analogues of both classes of ligands have been synthesized and evaluated. Amino thiol ligands tend to show the highest enantioselectivities due to the higher affinity of sulfur for zinc over zirconium. A new class of valine-based ligands was identified to be quite effective, in terms of ligand loading and % ee in the formation of allylic alcohols. In Chapter 2, progess toward pseudotrienic acid A is discussed. The goal of this project was the synthesis of pseudotrienic acid A utilizing alkenylzirconium/zinc methodology cultivated in the Wipf group and to elucidate the absolute configuration at C(20) of the target molecule. A brief summary of the only reported synthesis of pseudotrienic acid B by Cossy et al. is outlined, followed by the retrosynthetic plan and synthesis of the 3 main fragments of this molecule. Lastly, the current progress towards the coupling of these fragments is examined.
date: 2007-09-20
type: University of Pittsburgh ETD
type: PeerReviewed
format: application/pdf
language: en
identifier: http://d-scholarship-dev.library.pitt.edu/8937/1/Jayasuriyan_2007etdpitt.pdf
identifier:   Jayasuriya, Nilukshi Renuka  (2007) Asymmetric Alkenyl Zirconocene/Zinc Additions to Aldehydes and Synthetic Efforts Toward Pseudotrienic Acid A.  Doctoral Dissertation, University of Pittsburgh.    (Unpublished)