Oligomers of a 5-carboxy-methanopyrrolidine β-amino acid. A search for order.
نویسندگان
چکیده
CD spectra for homooligomers (n = 4, 6, 8) of (1S,4R,5R)-5-syn-carboxy-2-azabicyclo[2.1.1]hexane (MPCA), a methano-bridged pyrrolidine β-carboxylic acid, suggest an ordered secondary structure. Even in the absence of internal hydrogen bonding, solution NMR, X-ray, and in silico analyses of the tetramer are indicative of conformations with trans-amides and C(5)-amide-carbonyls oriented toward the C(4) bridgehead. This highly constrained β-amino acid could prove useful in the ongoing development of well-defined foldamers.
منابع مشابه
Helical folding of α/β-peptides containing β-amino acids with an eight-membered ring constraint.
αβα-Tripeptide that contains a cyclic β-amino acid with an eight-membered ring, a cis-2-aminocyclooct-5-enecarboxylic acid (cis-ACOE) or a cis-2-aminocyclooctanecarboxylic acid (cis-ACOC) displayed an 11/9-helical turn in the crystal state. The related α/β-peptide oligomers were shown to adopt 11/9-helical conformations in solution.
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ورودعنوان ژورنال:
- Organic letters
دوره 12 23 شماره
صفحات -
تاریخ انتشار 2010