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Formal Synthesis of Palmerolide a Using Fragmentation Methodology Marilda Pereira Lisboa

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Florida State University Libraries Electronic Theses, Treatises and Dissertations The Graduate School 2013 Formal Synthesis of Palmerolide a Using Fragmentation Methodology Marilda Pereira Lisboa Follow this and additional works at the FSU Digital Library. For more information, please contact [email protected] THE FLORIDA STATE UNIVERSITY COLLEGE OF ARTS AND SCIENCES FORMAL SYNTHESIS OF PALMEROLIDE A USING FRAGMENTATION METHODOLOGY By MARILDA PEREIRA LISBOA A Dissertation submitted to the Department of Chemistry and Biochemistry in partial fulfillment of the requirements for the degree of Doctor of Philosophy Degree Awarded: Spring Semester, 2013 Marilda Pereira Lisboa defended this dissertation on April 1, 2013. The members of the supervisory committee were: Gregory B. Dudley Professor Directing Dissertation Akash Gunjan University Representative Igor V. Alabugin Committee member Lei Zhu Committee member Michael Shatruk Committee member The Graduate School has verified and approved the above-named committee members, and certifies that the dissertation has been approved in accordance with university requirements. ii ACKNOWLEDGEMENTS The PhD is definitely a life changing experience. I gained knowledge, I learned how to build knowledge and I exchanged knowledge with various people during this journey. Without a doubt, the person that helped me the most during the process was my advisor Dr Gregory Dudley. I would like to thank Dr Dudley for all his support. In the beginning, I had no idea of how much I would learn from him, not only in the scientific level, but also in the personal level. I am grateful because I had the opportunity to work with a role model like Dr Dudley. There are countless other people that help me during the last five years. Without listing their names, I just want to thank everyone for their contributions and friendship: my friends from the Dudley lab, my friends from the other labs, my professors, my students, the staff from the Chemistry and Biochemistry Department, the janitors, my friends from UFMG in Brazil, Fulbright and Capes, my committee members, and my family… iii TABLE OF CONTENTS LIST OF TABLES .......................................................................................................................... v LIST OF FIGURES ....................................................................................................................... vi LIST OF ABBREVIATIONS ......................................................................................................... x ABSTRACT ................................................................................................................................. xiv CHAPTER 1 - PALMEROLIDE A ................................................................................................ 1 CHAPTER 2 - TOTAL SYNTHESES AND APPROACHES TOWARDS PALMEROLIDE A . 7 CHAPTER 3 - RING OPENING OF CYCLIC VINYLOGOUS ACYL TRIFLATES USING STABILIZED CARBANION NUCLEOPHILES ........................................................................ 41 CHAPTER 4 - FORMAL SYNTHESIS OF PALMEROLIDE A ............................................... 67 CHAPTER 5 - ENDEAVORS IN THE SYNTHESIS OF PALMEROLIDE A .......................... 91 CHATER 6 - FUTURE DIRECTIONS ...................................................................................... 112 APPENDIX A ............................................................................................................................. 114 APPENDIX B ............................................................................................................................. 121 APPENDIX C ............................................................................................................................. 138 REFERENCES ........................................................................................................................... 147 BIOGRAPHICAL SKETCH ...................................................................................................... 155 iv LIST OF TABLES Table 1 - V-ATPase inhibition versus cytotoxicity of palmerolides A, D, E, F and G.................. 3 Table 2 - Cytotoxicity of palmerolide A and some analogues. ...................................................... 6 Table 3 - Overview of the synthetic sequences to palmerolide A. ............................................... 39 Table 4 - Reaction of vinylogous acyl triflates with 1.1 equiv of phosphonate ...........................55 v LIST OF FIGURES Figure 1 - Structure of palmerolides A-G. ......................................................................................2 Figure 2 - First-generation of palmerolide A analogues. ............................................................... 4 Figure 3 - Second-generation of palmerolide A analogues. ........................................................... 6 Figure 4 - Retrosynthesis of proposed structure of palmerolide A. ............................................... 8 Figure 5 - Synthesis of fragment 29. .............................................................................................. 8 Figure 6 - Preparation of fragments 30 and 31. ............................................................................. 9 Figure 7 - De Brabander synthesis of proposed structure 28 and ent-1. ...................................... 10 Figure 8 - Retrosynthesis of proposed structure of palmerolide A. ............................................. 11 Figure 9 - Synthesis of fragment 40. ............................................................................................ 11 Figure 10 - Preparation of fragment 41. ....................................................................................... 12 Figure 11 - Preparation of fragment 42. ....................................................................................... 12 Figure 12 - Synthesis of proposed (28) and revised structure of palmerolide A (1). ................... 13 Figure 13 - Improvements in the synthesis reported by Nicolaou/Chen...................................... 14 Figure 14 - Alternative macrocyclization strategies for the synthesis of palmerolide A. ............ 15 Figure 15 - Organoboron methodologies developed in Hall lab. ................................................. 16 Figure 16 - Retrosynthesis of palmerolide A by Hall and coworkers. ......................................... 17 Figure 17 - Synthesis of fragment 56. .......................................................................................... 18 Figure 18 - Synthesis of fragment 57. .......................................................................................... 19 Figure 19 - Completion of the synthesis of palmerolide A. ......................................................... 19 Figure 20 - Retrosynthesis of palmerolide A by Maier group. .................................................... 20 Figure 21 - Preparation of fragments 81 and 82. ......................................................................... 21 Figure 22 - Preparation of fragment 69. ....................................................................................... 21 Figure 23 - Completion of Maier formal synthesis. ..................................................................... 22 vi Figure 24 - Retrosyntheses of palmerolide A according to Prasad group. .................................. 23 Figure 25 - Synthesis of fragment 40. .......................................................................................... 24 Figure 26 - Synthesis of fragment 89. .......................................................................................... 24 Figure 27 - Synthesis of the late intermediate 88 in Nicolaou/Chen synthesis. ........................... 25 Figure 28 - Synthesis of fragment 90. .......................................................................................... 25 Figure 29 - Synthesis of fragment 91. .......................................................................................... 26 Figure 30 - Completion of the formal synthesis of palmerolide A. ............................................. 26 Figure 31 - Retrosynthesis of palmerolide A as reported by Kaliappan group............................ 28 Figure 32 - Synthesis of fragment 111. ........................................................................................ 28 Figure 33 - Synthesis of fragment 112. ........................................................................................ 29 Figure 34 - Synthesis of fragment 113. ........................................................................................ 30 Figure 35 - Completion of Kaliappan formal synthesis. .............................................................. 30 Figure 36 - The C1-C14 fragment of palmerolide A by Chandrasekhar group. .......................... 30 Figure 37 - Synthesis of the C1-C14 fragment of palmerolide A. ............................................... 31 Figure 38 - Retrosynthesis of palmerolide A according to Meyer/Cossy group. ........................ 32 Figure 39 - Preparation of fragment 137. ..................................................................................... 32 Figure 40 - Preparation of fragment 138. ..................................................................................... 33 Figure 41 - Preparation of fragment 40. ....................................................................................... 33 Figure 42 - Preparation of fragment C3-C15. .............................................................................
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