| Abstract
| - Quantum mechanical methods have been used to investigate the intrinsic conformational preferences of 1-amino-2,2-diphenylcyclopropanecarboxylic acid (c3Dip), a cyclopropane analogue of phenylalanine bearing two phenylsubstituents on the same β-carbon. Geometries, energies, and frequencies were calculated on the N-acetyl-N‘-methylamide derivative at the HF and B3LYP levels using the 6-31G(d), 6-311G(d), and 6-31+G(d,p)basis sets. Four minimum energy conformations were characterized: axial C7, equatorial C7, right-handedhelix, and polyproline II. Analysis of the whole results, which are fully consistent with available experimentaldata, indicates that c3Dip tends to promote γ-turn conformations.
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