Hyperconjugation Effect in the Conformational Preference of Cyclohexene-Based β-Amino Acids

Key Points

• This research investigates how hyperconjugation affects the conformational preferences of cyclohexene-based β-amino acids.
• Analyzed two cyclohexene-based cyclic β-amino acids for their conformational preferences.
• Utilized NBO (Natural Bond Orbital) analysis to assess electronic interactions influencing conformations.
• cis-4-ACHE exhibits two conformations supporting right- and left-handed helical folding.
• cis-3-ACHE shows a preference for one conformation with pseudoaxial NH and pseudoequatorial CO groups, indicating strong hyperconjugation effects.
• NBO analysis highlights the interaction between π-orbital of the C=C bond and s* orbital of the C–N bond as a key factor.