Absolute configuration of (−)-myrtenal by vibrational circular dichroism

The VCD spectrum of the monoterpene (−)-myrtenal (1) was compared with theoretical spectra calculated for (1R)-1 using density functional theory (DFT) at the B3LYP/6-31G(d,p), B3LYP/6-31G+(d,p), B3LYP/6-311G+(d,p), B3LYP//DGDZVP, and B3PW91/DGTZVP levels of theory. The calculated spectra for the most stable conformer, using these hybrid functionals and basis set, show no significant changes, evidencing that B3LYP/DGDZVP calculations provide a superior balance between computer time and VCD spectral accuracy. It follows (−)-myrtenal is 1R.