ORGN 416 |
| Although our knowledge of carbohydrates is not yet complete, glycobiology lessons have already taught us that these fascinating natural compounds are involved in a broad range of vital biological processes. Carbohydrates are also responsible for many harmful processes in our cells, such as bacterial and viral infections, development and growth of tumors, metastasis, tissue rejection, septic shock, etc. Many of these processes are directly associated with various deadly diseases of the 21st century: AIDS, cancer, meningitis, septicemia, etc. Elucidation of the exact mechanisms of the carbohydrate involvement in disease pathogenesis would be greatly facilitated if we could rely on the comprehensive knowledge of the structure, conformation, and properties of the carbohydrate molecules. In the context of fair availability of natural complex carbohydrates, the development of stereoselective methods and convergent strategies for the synthesis of complex glycostructures has become critical for the field of glycosciences. To enhance the ability to synthesize complex carbohydrates, our laboratory invented novel classes of substituted glycosyl thioimidates, S-benzoxazolyl (SBox) and S-thiazolinyl (STaz) derivatives. It has been established that the SBox and STaz glycosides are reactive and stereoselective glycosyl donors. Their ability to withstand many standard reaction conditions associated with protecting group manipulations and activation of other classes of glycosyl donors has led us to a discovery of novel strategies for oligosaccharide assembly. Herein we present development of the temporary deactivation concept, an unprecedented O-2/O-5 cooperative effect in glycosylation, and the inverse armed-disarmed strategy. |
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New Reactions and Methodology
1:00 PM-5:20 PM, Tuesday, 12 September 2006 Moscone Center -- Room 133, Oral
Division of Organic Chemistry |