本文描述了以D-核糖為起始原料，通過分子內的Diels-Alder (IMDA) 反應來構建雙碳環，以及其在雙碳環核苷合成方面的研究。 / D-核糖 (20) 經丙酮化，乙烯化作用和乙二醇裂解反應 (在硅膠的輔助作用下)可以得到乳醇68。本文考察了通過不同的方法來合成關鍵中間體三烯65。三烯中間體 65 經氧化和環化，最終可以合成出雙環[4. 3. 0]壬烷結構的碳環物64。由D-核糖為起始原料，只需6 步驟就可以得到碳環物64[附圖]。 / 為了引入C -5'的羥基，進行了環氧化和環氧化物還原反應的研究。由碳環物64 開始通過10 至15 步，可以合成出一系列含新型的[4. 3. 0]結構碳環核苷59-62[附圖]。 / 以疊氮化炔的Huisgen 環加成反應(點擊化學)作為關鍵步，合成出一系列含新型的[4. 3. 0]結構碳環核苷利巴韋林類似物[附圖]。 / In this thesis, the construction of bicyclic carbocycle from D-Ribose via an intramolecular Diels Alder (IMDA) reaction and its application to the syntheses of carbobicyclic nucleosides are presented. / D-Ribose (20) underwent acetonation, vinylation, mild silica gel supported glycol cleavage to give the lactol 68. Different methods were studied in the synthesis of the key triene intermediate 65. Oxidation of the triene intermediate and employing IMDA reaction finally afforded the bicyclo[4.3.0]nonane framework carbocycle 64 in 6 steps from D-Ribose [With images]. / To install the C-5’ hydroxyl group, epoxidation and epoxide reduction reactions were studied and reported. A series of carbobicyclic nucleosides 59-62 with a novel bicyclo[4.3.0]nonane framework were synthesized from cycloadduct 64 in 10 to 15 steps [With images]. / The syntheses of a series of carbobicyclic ribavirin analogues with bicyclo[4.3.0]nonane framework using azide alkyne Huisgen cycloaddition (Click Chemistry) as the key step were also studied and reported [With images]. / Detailed summary in vernacular field only. / Detailed summary in vernacular field only. / Detailed summary in vernacular field only. / Detailed summary in vernacular field only. / Wong, Wing Ho Anthony. / Thesis (Ph.D.)--Chinese University of Hong Kong, 2012. / Includes bibliographical references (leaves 175-185). / Electronic reproduction. Hong Kong : Chinese University of Hong Kong, [2012] System requirements: Adobe Acrobat Reader. Available via World Wide Web. / Abstract also in Chinese. / Acknowledgment --- p.i / Table of Contents --- p.ii / Abstract --- p.iv / Abstract (Chinese Version) --- p.vi / Abbreviation --- p.vii / Chapter 1 --- Introduction --- p.1 / Chapter 1.1 --- General Background --- p.1 / Chapter 1.2 --- Conformation of nucleosides --- p.3 / Chapter 1.2.1 --- Conformation of conventional nucleosides --- p.3 / Chapter 1.2.2 --- Conformation of carbocyclic nucleosides --- p.7 / Chapter 1.3 --- Previous syntheses and development of conformationally locked carbocyclic nucleosides --- p.9 / Chapter 1.3.1 --- Synthesis of dideoxyribonucleosides in N conformation --- p.9 / Chapter 1.3.2 --- First enantioselective synthesis of 2’-Deoxyribonucleosides Analogues with N conformation --- p.10 / Chapter 1.3.3 --- Most recent synthesis of bicyclo[3.1.0]hexane system ribonucleoside analogue --- p.12 / Chapter 1.3.4 --- Synthesis of bicyclo[3.3.0]octane system carbocyclic nucleosides --- p.13 / Chapter 1.3.5 --- Synthesis of nucleosides with bicyclo[2.2.1]heptene/heptanes skeleton --- p.16 / Chapter 1.3.6 --- Synthesis of spirocarbocyclic nucleosides --- p.18 / Chapter 2 --- Results and Discussion --- p.20 / Chapter 2.1 --- Construction of Bicyclic Carbocycle via Intramolecular Diels-Alder Reaction (IMDA) --- p.20 / Chapter 2.1.1 --- Synthesis of triene precusor and the bicyclo[4.3.0]nonane framework --- p.21 / Chapter 2.1.2 --- Synthesis of triene precusor and the bicyclo[4.3.0]nonane framework using open chain approach --- p.27 / Chapter 2.1.3 --- Synthesis of triene precusor by the use of Wittig Reaction --- p.29 / Chapter 2.2 --- Attempted epimerization of C-6 position of the cycloadduct --- p.40 / Chapter 2.2.1 --- Attempted epimerization of cycloadduct 64 --- p.40 / Chapter 2.2.2 --- Attempted epimerization of saturated ketone 84 --- p.41 / Chapter 2.2.3 --- Attempted epimerization of diols 86 and 88 --- p.42 / Chapter 2.2.4 --- Attempted epimerize of dibenzyl ether 90 --- p.45 / Chapter 2.3 --- Synthesis of the target nucleosides --- p.47 / Chapter 2.3.1 --- Synthesis of alcohol 106 and 107 --- p.47 / Chapter 2.3.2 --- Attempted synthesis of target nucleosides by convergent method --- p.57 / Chapter 2.3.3 --- Synthesis of adenosine analogue 59 via linear methods --- p.62 / Chapter 2.3.4 --- Synthesis of thymidine analogue 60 and uridine analogue 61 --- p.68 / Chapter 2.3.5 --- Synthesis of citidine analogue 62 --- p.70 / Chapter 2.3.4 --- Attempted synthesis of guanosine analogue 63 --- p.75 / Chapter 2.4 --- Syntheses of ribavirin analogues by Click Chemistry --- p.78 / Chapter 2.4.1 --- Synthesis of 5’-deoxyribavirin analogues --- p.78 / Chapter 2.4.2 --- Synthesis of ribavirin analogues --- p.84 / Chapter 3 --- Conclusion --- p.89 / Chapter 4 --- Experimental Section --- p.95 / Chapter 5 --- References --- p.175 / Chapter 6 --- Appendix --- p.186 / X-ray crystallographic data and structures --- p.189 / NMR spectra --- p.207

The faithful replication of DNA depends on the appropriate balance of DNA precursors. From studies conducted in bacteriophage T4, models for deoxyribonucleotide biosynthesis producing pools appropriate for DNA replication have made it possible to understand more complex systems. A portion of that body of evidence supports the concept that deoxyribonucleotide biosynthesis for bacteriophage T4 is carried out by an association of enzymes and other cellular components in a complex called the dNTP synthetase complex. This dissertation explores potential direct protein-protein interactions within this complex for the preparation of pyrimidine deoxyribonucleotides. Direct associations for enzymes involved in pyrimidine deoxyribonucleotide biosynthesis were examined by affinity chromatography. It was determined that there was a significant direct relationship between T4 thymidylate synthase and T4 dCMP deaminase, between T4 dCTPase/dUTPase and T4 dCMP deaminase as well. The interaction between thymidylate synthase and dCMP deaminase was significantly influenced by the presence of dCTP, a positive effector of dCMP deaminase. Furthermore, protein associations changed the kinetic character of pyrimidine deoxyribonucleotide production. T4 dCTPase/dUTPase, a member of the dNTP synthetase complex, significantly alters the kinetic nature of thymidylate synthase by working with thymidylate synthase in a reciprocal relationship. T4 single-stranded DNA binding protein, a member of the replication complex, alters the activity of thymidylate synthase as well. Attempts to isolate a kinetically coupled complex from two or more constituent proteins of the dNTP synthetase complex were frustrated by protein degradation to fragments under 10 kDa in size. Pyrimidine deoxyribonucleotide synthesis is located between the significant energy investment of ribonucleotide reductase and phosphate attachments by kinases to prepare the deoxyribonucleotide molecules for DNA replication. In bacteriophage T4, intermediate reactions are driven by mass action but are modulated by subtleties including direct protein associations and the presence of small molecules that influence enzyme function. Through these and potentially similar controls, pools of deoxyribonucleotides are prepared and delivered in a timely, balanced manner to the DNA replication apparatus. / Graduation date: 2002

published_or_final_version / Biochemistry / Doctoral / Doctor of Philosophy