Date of Award

Spring 2013

Document Type

Thesis

Terms of Use

© 2013 Alice R. Wong. All rights reserved. This work is freely available courtesy of the author. It may only be used for non-commercial, educational, and research purposes. For all other uses, including reproduction and distribution, please contact the copyright holder.

Degree Name

Bachelor of Arts

Department

Chemistry & Biochemistry Department

First Advisor

Robert S. Paley

Abstract

Enantiomerically pure planar chiral iron(0) tricarbonyl diene complexes were used as a template for the diastereoselective spiroketalization of four spiroketals. As an additional complication, these substrates contained an additional methyl substituent (both the (R) and (S) configurations) at the C6 position along the B ring of the spiroketal; these substituent effects were examined for both the 2-iodovinyl sulfoxide and l-iodovinyl sulfoxide series. These spiroketalization reactions demonstrated clear "matched"/"mismatched" effects as predicted, affording "matched" spiroketalization diastereomeric ratios of 46:1 and 24:1, and "mismatched" spiroketalization diastereomeric ratios of 10:1 and 9:l. These diastereoselectivities were supported by computational information. As a step away from this chemistry, an enantiomerically pure [6,6] azaspirocycle was synthesized in high diastereoselectivity using a planar chiral iron(O) tricarbonyl diene complex to direct the stereochemistry at the azaspirocyclic stereocenter. This synthesis includes the first enantiopure cyclic imino iron(0) tricarbonyl diene complex. Diastereoselective allylation of the cyclic imino iron(0) tricarbonyl diene complex afforded a single diastereomer. This was followed by ring-closing metathesis to yield the azaspirocycle. The absolute relative stereochemistry of the azaspirocyclic center was determined via x-ray crystallography. Finally, the absolute stereochemistry of the major and minor facial diastereomers of an iron(0) tricarbonyl complexation to an enantiopure N-oxazolidinyl diene complex were established via x-ray crystallography.

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