Synthetic approaches to structurally complex molecules by photo- and non-photochemical methods / Hyunil Jo.

Format:

Book

Manuscript

Microformat

Thesis/Dissertation

Author/Creator:

Jo, Hyunil.

Contributor:

Winkler, Jeffrey D., advisor.

Joullié, Madeleine M., advisor.

University of Pennsylvania.

Language:

English

Subjects (All):

Penn dissertations--Chemistry.

Chemistry--Penn dissertations.

Local Subjects:

Penn dissertations--Chemistry.

Chemistry--Penn dissertations.

Physical Description:

xvii, 226 pages : illustrations ; 29 cm

Production:

2008.

Summary:

This dissertation details the development and investigation of three independent research projects. These aims show a progressive evolution from ground state chemistry to excited state chemistry and finally supramolecular chemistry in construction and design of structurally complex molecules.

The first section shows the synthetic approaches toward a potent microtubule stabilizing natural product, elutherobin, utilizing tandem Diels-Alder reaction/Grob-type fragmentation reaction as key steps. During the course of these studies, large scale preparation of bis-diene and successful activation of the secondary alcohol were achieved. Due to the difficulty in SmI 2 fragmentation and the capricious nature of the tandem Diels-Alder reaction, our original route did not prove amenable to an efficient synthesis of eleutherobin. A revised route using a beta-elimination pathway was subsequently investigated.

The following section has its foundation based upon a serendipitous discovery in the Winkler group. In an effort to explore the scope of the photoreaction, we found a novel desulfurative photocycloaddition from investigation of enone-benzothiazoline photochemistry and its mechanistic rationale was studied to suggest enecarbamate could be an intermediate that was generated from its episulfide precursor. The formation of N,S-acetal photoproduct could be also utilized in the synthesis of another natural product, discorhabdin A.

The concluding section deals with a synthetic design of chiral molecular tweezers based upon the natural alkaloid calycanthine. A number of synthetic strategies on the extended dimer of calycanthine were investigated and monobromocalycanthine was successfully prepared from a semi-synthetic approach. The future directions of this project based on dimethylcalycanthine are presented.

Notes:

Advisers: Jeffrey D. Winkler; Madeleine M. Joullie.

Thesis (Ph.D. in Chemistry) -- University of Pennsylvania, 2008.

Includes bibliographical references.

Local Notes:

University Microfilms order no.: 3346138