ORGN 55 |
| Nucleoside analogues are part of the most important biologically and pharmaceutically active class of compounds used for treating many cancers and viral infections. The emergence of virus resistance to these drugs and the need to control other viruses and cancers require that novel drugs be identified. Herein, we present a new synthetic route to gain access to nucleosides and 4'-thionucleoside analogues from acyclic dithioacetals. The first step involves a diastereoselective base coupling leading to the formation of a thioaminal. This adduct can then be cyclized to give nucleoside analogues via displacement of the activated sulfide of the thioaminal (C4'-C1' cyclization mode). Alternatively, converting the C4' alcohol into a leaving group and employing the sulfur atom as a nucleophile allows the synthesis of 4'-thionucleosides (C1'-C4' cyclization mode). Studies aimed at unraveling the reaction mechanisms involved will be presented as well as the scope and limitations of the reaction sequence.
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New Reactions and Methodology
8:00 AM-12:00 PM, Sunday, August 19, 2007 BCEC -- 258B, Oral
Division of Organic Chemistry |
