An Assessment of Alternative Low Level Calculation Methods for the Initial Selection of Conformers of Diastereomeric Esters

Figure 2

Flow chart of the calculations (Step 1: generation of conformers followed by the initial optimization using MM3 method; Step 2: optimization of the conformers by using LLMs; Step 3: single-point calculation of the conformer energies by using the reference method DFT B3LYP/6-311++G** (RefM1); Step  4: the sequential optimization cascade of conformational analysis (RefM2); Step 5: optimization of the refined conformers for their identification by using the LLMs) performed.