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I the Synthesis of Papyracillic Acids: Application of the Tandem Chain University of New Hampshire University of New Hampshire Scholars' Repository Doctoral Dissertations Student Scholarship Winter 2011 I The synthesis of papyracillic acids: Application of the tandem chain extension-acylation reaction II Diastereoselective synthesis of beta-methyl-gamma-keto esters through the utility of an L- serine auxiliary Jennifer R. Mazzone University of New Hampshire, Durham Follow this and additional works at: https://scholars.unh.edu/dissertation Recommended Citation Mazzone, Jennifer R., "I The synthesis of papyracillic acids: Application of the tandem chain extension- acylation reaction II Diastereoselective synthesis of beta-methyl-gamma-keto esters through the utility of an L-serine auxiliary" (2011). Doctoral Dissertations. 644. https://scholars.unh.edu/dissertation/644 This Dissertation is brought to you for free and open access by the Student Scholarship at University of New Hampshire Scholars' Repository. It has been accepted for inclusion in Doctoral Dissertations by an authorized administrator of University of New Hampshire Scholars' Repository. For more information, please contact [email protected]. I. THE SYNTHESES OF PAPYRACILLIC ACIDS: APPLICATION OF THE TANDEM CHAIN EXTENSION-ACYLATION REACTION II. DIASTEREOSELECTIVE SYNTHESIS OF p-METHYL-y-KETO ESTERS THROUGH THE UTILITY OF AN L-SERINE AUXILIARY BY Jennifer R. Mazzone B.A., Assumption College, 2006 DISSERTATION Submitted to the University of New Hampshire in Partial Fulfillment of the Requirements for the Degree of Doctor of Philosophy in Chemistry December, 2011 UMI Number: 3500790 All rights reserved INFORMATION TO ALL USERS The quality of this reproduction is dependent upon the quality of the copy submitted. In the unlikely event that the author did not send a complete manuscript and there are missing pages, these will be noted. Also, if material had to be removed, a note will indicate the deletion. UMI Dissertation Publishing UMI 3500790 Copyright 2012 by ProQuest LLC. All rights reserved. This edition of the work is protected against unauthorized copying under Title 17, United States Code. uest ProQuest LLC 789 East Eisenhower Parkway P.O. Box 1346 Ann Arbor, Ml 48106-1346 DEDICATION This dissertation is dedicated to my parents Donna and Frank Mazzone The admiration I have for you both far exceeds what I am able to express in words. Thank you for teaching me many lessons that could not be learned in a classroom. in ACKNOWLEDGEMENTS The entire Department of Chemistry at the University of New Hampshire has contributed to my graduate studies and facilitated the completion of this dissertation. I am especially indebted to my mentor and advisor, Professor Charles K. Zercher for accepting me into his research group and guiding me through this immense journey. Dr. Zercher's wealth of knowledge in the field of organic synthesis is a constant source of personal amazement. His consistent guidance, his dedication to teaching in the classroom and laboratory are gifts, which can never be repaid. I am thankful to my committee members, Prof. Margaret E. Greenslade, Prof. Richard P. Johnson, and Prof. Arthur Greenberg for their constructive criticism and insight into my research. I had the pleasure of taking classes with Prof. Gary R. Weisman and Prof. Roy P. Planalp. Their courses are among the best classes I attended. In addition the expertise and advice of faculty members, Prof. Edward H. Wong and Prof. Sterling A. Tomelini are counted as valuable resources. Thank you to Cindi Rohwer, Peg Torch, Jane Austin, Kristen Blackwell, and Bob Constantine for keeping the chemistry department running smoothly! I am especially thankful to Dr. Patricia Wilkinson for her assistance with the NMR spectrometer and other instrumentation. Her friendly encouragement and advice was always appreciated. Thank you to Prof. Glen P. Miller and John Briggs for running several of our samples on their X-ray crystal diffraction instrument. Thank you to Andy Hanneman, from the Department of Molecular, Cellular, and Biomedical Sciences, for taking time to run a mass spec, for us on very short notice. iv I am fortunate for my current group members, Carley Spencer, Deepthi Bhogadhi, Matt Mower, and Peter Moran. They have offered support, discussed chemistry, and kept me company during many late nights in lab. Additional colleagues and friends, Justin Massing, Barbra Li, Leon Wong, Nick Bencivenga, Joe Dun, Matt Young, and Greg Bubnis have contributed to my experience as well. Thank you to Rajesh Thamatam for his advice and suggestions. His dedication to research inspired and strengthened my work ethic. Early on the path as a graduate researcher, the most memorable experiences were followed by the support of my former group members. At pivotal moments Alex Jacobine, Ian Taschner, and Tim Henderson offered indispensable advice and moral encouragement. I am especially thankful to Aida Ajaz for her friendship and steady support. I am most grateful she was brave enough to leave her home country and start a new life at UNH. We were destined to be lifelong friends. I am most grateful to my parents, Donna and Frank Mazzone. Their personal sacrifice and example imparted high values on education and lifelong learning. I am thankful to my sister, Katherine Mazzone. Despite the miles that separate us, Katie was the one person who could make me laugh during the chaos and stress of this vast journey. Finally, I would like to thank the National Institute of Health, the University of New Hampshire Graduate School, and the Department of Chemistry for funding this research. v TABLE OF CONTENTS DEDICATION iii ACKNOWLEDGEMENTS iv LIST OF SCHEMES xiv LIST OF FIGURES xxi LIST OF TABLES xxiii LIST OF ABBREVIATIONS xxv ABSTRACT xxvii CHAPTER PAGE I. INTRODUCTION 1 Proteases 1 Peptide Isosteres 3 Zinc Carbenoid-Mediated Chain Extension Reaction 9 Synthesis of Ketomethylene Isosteres using the Chain Extension Reaction... 17 Formation of a-Functionalized y-Keto Carbonyls 18 i Formation of (3-Functionalized y-Keto Carbonyls 27 vi Natural Product Synthesis using the Chain Extension Reaction 31 II. SYNTHESES OF PAPYRACILLIC ACIDS: APPLICATION OF THE TANDEM CHAIN EXTENSION-ACYLATION REACTION 39 Papyracillic Acids 39 Synthetic Approach 42 Tandem Chain Extension-Acylation Reaction using Maleic Anhydride 44 Other Anhydrides 54 Carbodiimide-Mediated Heterocycle Formation 59 Synthesis of Spiro-Fused Ketal Cores 64 Equilibration Studies 70 Stereochemical Assignment for the Major Diastereomer 74 Synthesis of Papyracillic Acid C 80 Synthesis of 4-ep/-Papyracillic Acid B and Papyracillic acid B 99 III. DIASTEREOSELECTIVE SYNTHESIS OF B-METHYL y-KETO ESTERS THROUGH THE UTILITY OF AN L-SERINE AUXILIARY 109 Synthesis of B-Substituted-y-Keto Esters 109 Previous Attempts at Controlling the Stereochemistry 112 Amino Acid-Derived Systems 114 Hydroxyl-Directed Simmon-Smith Cyclopropanation Reactions 118 Synthesis and Results of L-Serine Derived Auxiliary 120 Quantifying the Diastereoselectivity 127 vii Elucidation of the Stereochemistry 129 Attempts at Synthesizing Hydroxyl L-Serine Auxiliary 138 Boc-Protecting Group Problems 141 Lactic Acid Derived System 145 Future Application for the L-Serine Derived Auxiliary 147 EXPERIMENTAL SECTION 149 General Experimental Section 149 Detailed Experimental Section 151 Compound 35c. Methyl 4,4-dimethyl-3-oxopentanoate (methyl pivaloylacetate) 151 Compound 42e. Allyl 3-oxobutanoate 152 Compound 90. 1,1-Diiodoethane 153 Compounds 134. 3-Methoxyfuran-2,5-dione (3-methoxymaleic anhydride) 153 Compounds 144. £)-5-(Methoxycarbonyl)-8,8-dimethyl-4,7-dioxonon-2-enoic acid.. 154 Compounds 155. (2£,4£)-4-Hydroxy-5-(methoxycarbonyl)-8,8-dimethyl-7-oxonona-2,4- dienoic acid 154 Compound 152. (£)-4J-Dioxo-5-(2-oxooxazolidine-3-carbonyl)oct-2-enoic acid 155 Compound 165. 5-(Methoxycarbonyl)-8,8-dimethyl-4,7-dioxononanoic acid 156 Compound 166. Methyl 2-(2-hydroxy-5-oxotetrahydrofuran-2-yl)-5,5-dimethyl-4- oxohexanoate 156 Compound 167. Methyl 2-(fert-butyl)-2-hydroxy-7-oxo-l,6 dioxaspiro[4.4]nonane-4- carboxylate 156 Vlll Compound 171. 4-Ethoxy-4-oxobut-2-ynoic acid 157 Compound 182. Ethyl 2-(l,3-dicyclohexyl-2,5-dioxoimidazolidin-4- ylidene)acetate 158 Compound 183. Ethyl 2-(l,3-diisopropyl-2,5-dioxoimidazolidin-4- ylidene)acetate 159 Compound 185. 3-Phenylpropiolic acid 160 Compound 186. 5-Benzylidene-1,3-dicyclohexylimidazolidine-2,4-dione 160 Compound 194. Dimethyl 2-methoxybut-2-enedioate 160 Compound 195. 2-Methoxybut-2-enedioic acid 161 Compound 198a-C. Methyl 2,6-dimethoxy-2-methyl-8-oxo-l-oxaspiro[4.4]non-6-ene-4- carboxy late 162 Compound 200. Methyl 2-hydroxy-9-methoxy-2,3-dimethyl-7-oxo-l,6- dioxaspiro[4.4]non-8-ene-4-carboxylate 164 Compound 201. (£)-3-memoxy-5-(methoxycarbonyl)-6-methyl-4,7-dioxooct-2-enoic acid 164 Compound 203a-d. Methyl 2,9-dimethoxy-2,3-dimethyl-7-oxo-l,6-dioxaspiro[4.4]non-8- ene-4-carboxylate 166 Compound 204. (5/?,7/?,85*,9/?)-9-(Hydroxymethyl)-4,7-dimethoxy-7,8-dimethyl-l,6- dioxaspiro[4.4]non-3-en-2-one 167 Compound 205. (2i?,3S,4£5/?)-2,9-Dimethoxy-2,3-dimethyl-7-oxo-l,6- dioxaspiro[4.4]non-8-ene-4-carboxylic acid 170 Compound 206. 2,2-Dimethyl-l,3-dioxane-4,6-dione (Meldrum's acid) 171 Compound 208. 5-( 1 -Hydroxyethylidene)-2,2-dimethyl-l,3-dioxane-4,6-dione 171 IX Compound 210. Allyl 2-hydroxy-9-methoxy-2,3-dimethyl-7-oxo-l,6- dioxaspiro[4.4]non-8-ene-4 carboxylate 172 Compound 211. (2R,3SAS,5R)-A\\yl 2,9-dimethoxy-2,3-dimethyl-7-oxo-l,6- dioxaspiro[4.4]non-8-ene-4-carboxylate 171 Compound 218. (57?,7J/?,85,9i?)-7-hydroxy-9-(hydroxymethyl)-4-methoxy-7,8-dimethyl- l,6-dioxaspiro[4.4]non-3-en-2-one (4-e/?z'-papyracillic acid C) 175 Compound 219. (2R,3SAS,5R)-Ally\ 9-methoxy-2,3-dimethyl-7-oxo-2-(2,2,2- trichloroethoxy)-l ,6-dioxaspiro[4.4]non-8-ene-4-carboxylate 175 Compound 220.
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