Related Experiment Video
Updated: Mar 1, 2026

Enzymatic Cascade Reactions for the Synthesis of Chiral Amino Alcohols from L-lysine
Published on: February 16, 2018
Chiral differentiation of d- and l-alanine by permethylated β-cyclodextrin: IRMPD spectroscopy and DFT methods
Sung-Sik Lee1, Soojin Park, Yin Hong
1Department of Applied Chemistry, Kyung Hee University, Gyeonggi 446-701, Republic of Korea. sylee@khu.ac.kr.
Abstract:
The gaseous chiral differentiation of alanine by permethylated β-cyclodextrin was studied using IRMPD spectroscopy and density functional theory calculations. The protonated non-covalent complexes of permethylated β-cyclodextrin and d- or l-alanine were mass-selected and investigated by IR laser pulses in the wavelength region of 2650-3800 cm-1. The remarkably different features of the IRMPD spectra for d- and l-alanine are described, and their origin is elucidated by quantum chemical calculations. We show that the differentiation of the experimentally observed spectral features is the result of different local interactions of d- and l-alanine with permethylated β-cyclodextrin. We also assign the extremely high-frequency (>3700 cm-1) bands in the observed spectra to the stretch motions of completely isolated alanine -OH groups.
Related Concept Videos
Prochirality
Properties of Enantiomers and Optical Activity
¹³C NMR: Distortionless Enhancement by Polarization Transfer (DEPT)
¹H NMR Chemical Shift Equivalence: Enantiotopic and Diastereotopic Protons
In chiral compounds such as 2-butanol, replacing the methylene hydrogens at C3 produces a pair of...
¹H NMR of Conformationally Flexible Molecules: Variable-Temperature NMR
Chirality
Chiral objects exhibit a sense of handedness when they interact with another chiral object. For example, our left foot can only fit in the left shoe and not in the right shoe. Achiral objects — objects that have...

