Absolute Configuration Assignment of a Paraconic Acid Derivative via Vibrational Circular Dichroism Spectroscopy and Density Functional Theory Calculation

Abstract

Density functional theory calculation of the vibrational circular dichroism spectrum was used to assign the absolute configuration of an all-carbon quaternary β-stereocenter of a γ-butyrolactone recently synthesized through an asymmetric organocatalytic tandem aldol/lactonization sequence. Comparison with the experimental spectrum is satisfactory, on account of the fact that spectroscopic features are weak due to the presence of multiple conformers. As a result, the (R) absolute configuration was assigned to the (+) optical isomer.

Keywords: absolute configuration; density functional theory; paraconic acid derivatives; quaternary stereocenters; vibrational circular dichroism; γ-butyrolactones.