*3.6. Computational Section*

Conformational searches were carried out via molecular mechanics with the MM+ method in HyperChem 8.0 software (Gainesville, FL, USA). Afterwards, the geometries were optimized at the gas-phase B3LYP/6-31G level in Gaussian09 software to afford the energy-minimized conformers. Then, the optimized conformers were subjected to the calculations of ECD spectra using the TD-DFT at BH&HLYP/TZVP level for **4** and PBE0/TZVP level for **5**. Simultaneously, solvent effects of the MeOH solution were evaluated at the same DFT level using the SCRF/PCM method [20].
