DOI

10.17077/etd.dyx8-qhj7

Document Type

Dissertation

Date of Degree

Fall 2018

Access Restrictions

Access restricted until 01/31/2020

Degree Name

PhD (Doctor of Philosophy)

Degree In

Chemistry

First Advisor

Wiemer, David F.

First Committee Member

Gloer, James B.

Second Committee Member

Pigge, F. Christopher

Third Committee Member

Shaw, Scott K.

Fourth Committee Member

Forbes, Tori Z.

Abstract

The terpene and terpenoid family of compounds is considered to be the largest group of natural products. These compounds not only display great diversity in their structural features but are also known to have a multitude of biological activities including but not limited to anti-bacterial, anti-cancer, anti-inflammatory, and anti-HIV properties. Remarkably, all the terpenoids formed in nature come from two molecules viz. isopentenyl pyrophosphate and its isomer, dimethylallyl pyrophosphate both consisting of just five carbons but assembled in many ways. Nature utilizes highly efficient, enzyme-mediated cascade reactions to transform simple linear molecules to more complex cyclic scaffolds.

Cascade or domino reactions are organic chemistry’s most powerful tools that, if executed correctly, mimic the extreme complexity of reactions occurring in nature. Our group has successfully utilized cationic cascade cyclization reactions, to prepare a large library of natural products along with their analogues. It was during the synthesis of one such natural product that it was discovered that a methoxymethyl (MOM) “protecting group” had been transferred within the same molecule. The optimization of this process not only allowed the synthesis of the desired tricyclic framework but also resulted in the liberated MOM group doing an EAS reaction which gave a new C-C bond. This transferred MOM group was further elaborated to different functional groups.

Use of the tandem reaction sequence in an attempt to prepare radulanin E has been described. Total syntheses of two chalcone-based analogous meroterpenoids have been successfully completed using the aforementioned sequence. An advanced intermediate for an entire new class of acridine-based schweinfurthins has been elaborated. The results will be discussed in detail.

Keywords

Cascade reaction, Natural product chemistry, Organic synthesis, Total synthesis

Pages

xix, 214 pages

Bibliography

Includes bibliographical references (pages 205-214).

Copyright

Copyright © 2018 Parin Ajay Shah

Available for download on Friday, January 31, 2020

Included in

Chemistry Commons

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