Oligomers of a 5-carboxy-methanopyrrolidine β-amino acid. A search for order.
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.
Department of Chemistry, Temple University, Philadelphia, Pennsylvania 19122, USA. grkrow@temple.edu
Grant R
GR
Krow
Nian
N
Liu
Matthew
M
Sender
Guoliang
G
Lin
Ryan
R
Centafont
Philip E
PE
Sonnet
Charles
C
DeBrosse
Charles W
CW
Ross
Patrick J
PJ
Carroll
Matthew D
MD
Shoulders
Ronald T
RT
Raines
D000596:Amino Acids / Q000737:chemistry*; D008958:Models, Molecular; D015394:Molecular Structure; D011759:Pyrrolidines / Q000737:chemistry*
D000596:Amino Acids; D011759:Pyrrolidines