Chiroptical spectroscopic studies for the absolute configuration determination of hexahydrocurcumin and octahydrocurcumin

Hexahydrocurcumin (HHC) and octahydrocurcumin (OHC) were synthesized, and their enantiomers were separated using supercritical fluid chromatography. The absolute configurations (ACs) of HHC and OHC were independently determined using experimental measurements and quantum theoretical predictions of vibrational circular dichroism, electronic circular dichroism, and optical rotatory dispersion. These studies lead to AC assignments of (-)-(R)-HHC and (+)-(R,R)-OHC. The AC of OHC is further confirmed by its structure determined from single crystal x-ray diffraction.

Automated summary

Hexahydrocurcumin (HHC) and octahydrocurcumin (OHC) were synthesized and their enantiomers were separated. The absolute configurations (ACs) of HHC and OHC were determined using experimental measurements and quantum theoretical predictions. The AC assignments were (-)-(R)-HHC and (+)-(R,R)-OHC. The AC of OHC was further confirmed by its structure determined from single crystal x-ray diffraction.