ORGN 467 |
| A library of 8 beta-turn mimics was synthesized via copper-mediated azide/alkyne cycloadditions. The linear precursors 1 were recrystallized and isolated in an overall average yield of 70 %. Thus the substrates were conveniently accessible in gram amounts via syntheses that could be performed in parallel. Intramolecular and intermolecular cyclization of the linear precursors generated “monomeric” and “dimeric” products. Deprotection of the monomeric products proceeded cleanly to give the unmasked materials 2. Conformational analyses of selected macrocycles 2 were performed by simulating preferred conformations via the quenched molecular dynamics technique without any physical constraints. Bond parameters for low energy conformations were then compared to those measured from 1H NMR, ROESY, temperature coefficient studies, and coupling constants. These data are consistent with the computational predications and indicate that the solution conformation can adopt beta-turn shape.
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Modern Acetylene Chemistry
8:00 PM-10:00 PM, Tuesday, 12 September 2006 Moscone Center -- Hall D, Poster
Division of Organic Chemistry |
