| The dissertation describes my Ph.D. work focused on the synthesis of biologically relevant natural products and drug derivatives, which includes synthetic efforts toward carbohydrate-linked cisplatin analogs, αGal-conjugated antiviral agents and two uncommon branched amino sugars. A slightly different topic involving a novel oxidative cleavage of benzylidene acetals is also presented.; In the cisplatin project, three novel carbohydrate-linked cisplatin analogs, namely Gluco-, Lacto- and αGal-cisplatin, were designed and efficiently synthesized. The structure of Gluco-cisplatin was unambiguously confirmed by X-ray single crystal determination, and it demonstrates comparable antitumor activity as cisplatin itself.; In the antiviral agent project, an efficient chemo-enzymatic synthesis of a series of αGal-conjugated antiviral agents has been developed and their binding affinities to anti-Gal antibody were established. The promising anti-Gal binding ability of one of the compounds will be explored for the design and synthesis of more such conjugates. Other related synthetic efforts in the context of the antiviral project are also described in this section.; As the very first stage in the total synthesis of saccharomicins, synthetic studies toward two uncommon branched-chain amino sugars are presented in Chapter 3. Both conventional synthesis and more modern methodologies were emplored during the synthesis of saccharosamine and 4-epi-vancosamine.; In Chapter 4, a facile procedure is reported for the oxidative cleavage of benzylidene acetals using molecular oxygen catalyzed by N-hydroxyphthalimide/Co(OAc) 2. The methodology is environmentally benign and experimentally simple, and utilizes mild reaction conditions compatible with common carbohydrate protecting groups.; Finally, Chapter 5 gives a very brief description of the synthesis of a mannoside derivative of 10,12-pentacosadiynoic acid that was used in surface chemistry study. |
