open access

https://hdl.handle.net/2115/87938

Deuterium labelling to extract local stereochemical information by VCD spectroscopy in the C–D stretching region : a case study of sugars

英語

2022-02-07

Royal Society of Chemistry

Organic & Biomolecular Chemistry

20(5)

1067-1072

Stereochemical elucidation of molecules with multiple chiral centers is difficult. Even with VCD spectroscopy, excluding all but one diastereomeric structural candidates is challenging because stereochemical inversion of one chiral center among many centers does not always result in noticeable differences in their VCD spectra. This work demonstrates that introduction of a suitable VCD chromophore with absorption in the 2300-1900 cm-1 region can be used for extracting local stereochemical information and for stereochemical assignment of C-1 of various sugars as a case study. Through studies on a series of epimeric pairs of monosaccharides and their derivatives, we found that the introduction of one -OCD3 group to each C-1 position produced almost mirror-image VCD patterns in the 2300-1900 cm-1 region depending on the C-1 stereochemistry irrespective of the other molecular moiety. This work also shows that comparison of the observed VCD signals in this spectral region and calculated ones enables the stereochemical assignment of a chiral center in the vicinity of the chromophore. This study provides a proof of concept that the use of a VCD chromophore in the 2300-1900 cm-1 region enables the analysis of selected stereochemistry of suitable molecular systems. Further studies on this concept should lead to development of a method useful for the structural elucidation of other types of complex molecules.

学術雑誌論文

Accepted Manuscript

1477-0520

1477-0539

AA1168650X