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Absolute configuration assignment of (+)‐fluralaner using vibrational circular dichroism
Author(s) -
Kong John,
Joyce Leo A.,
Liu Jinchu,
Jarrell Tiffany M.,
Culberson J. Chris,
Sherer Edward C.
Publication year - 2017
Publication title -
chirality
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.43
H-Index - 77
eISSN - 1520-636X
pISSN - 0899-0042
DOI - 10.1002/chir.22770
Subject(s) - vibrational circular dichroism , absolute configuration , chemistry , enantiomer , circular dichroism , solvation , molecule , infrared , amide , crystallography , infrared spectroscopy , computational chemistry , stereochemistry , organic chemistry , physics , optics
Abstract The absolute configurations of the separated enantiomers of fluralaner, a racemic animal health product used to prevent fleas and ticks, have been assigned using vibrational circular dichroism (VCD). The crystallographic structure of the active enantiomer (+)‐fluralaner has previously been shown to have the ( S ) configuration using small molecule crystallography. We sought a faster analytical method to determine the absolute configuration of the separated enantiomers. When comparing the measured IR (infrared) and VCD spectra, it is apparent that the amide carbonyl groups appear in the IR but are nearly absent in the VCD. Computational work to calculate the VCD and IR using in vacuo models, implicit solvation, and explicitly solvated complexes has implicated conformational averaging of the carbonyl VCD intensities.