Absolute Configuration Assignment of (3-Phenyloxirane-2,2-diyl)bis(phenylmethanone) via Density Functional Calculations of Optical Rotation and Vibrational Circular Dichroism

作者：Lattanzi Alessandra; Russo Alessio; Rizzo Paola; Monaco Guglielmo; Zanasi Riccardo^*

来源：Chirality, 2010, 22(1E): E130-E135.

DOI：10.1002/chir.20856

• absolute configuration
• density functional theory
• optical rotation
• vibrational circular dichroism
• chiral epoxide

Density Functional Theory (DFT) calculations of optical rotation (OR) and vibrational circular dichroism (VCD) have been used to assign the absolute configuration (AC) of a recently prepared (3-phenyloxirane-2,2-diyl)bis(phenylmethanone), 3, by asymmetric epoxidation of the corresponding 2-arylidene-1,3-diketone. The experimental OR at 589.3 nm and the VCD spectrum of the (+)- and (-)-enantiomer of 3 have been measured. The conformationally-averaged OR value and VCD spectrum of (R)-3 were calculated at B3LYP/6-311G(2d,2p) level of theory. Both approaches provide the same absolute configuration of the stereogenic carbon, i.e. the AC of (+)-3 is (R)-3, thus affording a confident assignment. Only two conformational isomers of 3 have been predicted to be populated at ambient temperature. Their presence is directly observed in the VCD spectrum. Chirality 22:E130-E135, 2010.

• 出版日期2010