Vibrational circular dichroism DFT study on bicyclo[3.3.0]octane derivatives

The absolute configurations of four bicylco[3.3.0]octane derivatives: endo-bicyclo[3.3.0]octane-2,6-diol, endo-2,6-diacetoxybicyclo[3.3.0]octane, endo-bicyclo[3.3.0]octane-2,6-dione and bicyclo[3.3.0]octa-2,6-dien-2,6-bistriflate were studied by vibrational circular dichroism (VCD). These chiral derivates are of interest as intermediates in the asymmetric synthesis of enantiomerically pure natural products and chiral ligands for asymmetric catalysis. VCD has been used to determine the absolute configuration of each compound, proving the capability of VCD for molecules with several stereogenic centres. IR and VCD spectra have been simulated at the B3LYP/6-31G∗ level for all possible diastereomers. Based on the agreement between the experimental and the calculated spectrum, the stereochemistry of each compound could be assigned. The predicted absolute configurations are found to agree with literature data.