ORGN 435 |
| Natural conjugation of glycosides to proteins not only confers physico-chemical constraints on the protein, but the glycans serve as specific ligands for endogenous and exogenous receptors, and hence mediate various biological interactions. Replacing the linking oxygen or nitrogen with a methylene offers a great deal of stability to these conjugates with minimal steric variance. The ruthenium-catalyzed olefin cross-metathesis (CM), followed by hydrogenation, has been employed for the synthesis of alpha- and beta-C-glycosyl amino acids providing a rapid entry into analogues in which the intervening carbon chain contains three methylenes. Shorter carbon chains require an alternative CM or ring-closing metathesis approach on heptenitols to produce acyclic glyco-amino acid alkenes, which upon electrophilic cyclization yield the desired C-glycosyl amino acids with alpha- or beta-selectivity depending on alkene geometry.
|
|
ACS Award for Research at an Undergraduate Institution
8:00 AM-12:00 PM, Wednesday, 29 March 2006 Georgia World Congress Center -- C303/304/305, Oral
Division of Organic Chemistry |
