Synthesis and the absolute configurations of isoflavanone enantiomers

Abstract

Isoflavanone has been synthesized from the reduction of isoflavone in nearly quantitative yield. Isoflavone with seven equivalents of ammonium formate in the presence of Pd/C in ethanol under N2 atmosphere exclusively produced the two-electron reduced product in two hours. It was characterized by various spectroscopic methods, including UV-VIS, EI-MS, 1H-NMR, 13C-NMR and 1H, 1H-COSY. The racemic mixture was separated by Sumi-Chiral column chromatography and the absolute configurations of the enantiomers were characterized by circular dichroism spectroscopy.