## 3 Results and Discussion
### Chiral HPLC-DAD Analysis of Lactates  
The racemic products ((\(\pm\))-**1b**, **2b** and **3b**) were synthesized in previous steps and injected using different chiral columns and conditions (Supplementary Materials, Figure S14). The best separation conditions for racemic lactates (**1b**-**3b**) are reported in Table 2. The peaks chosen as representative of enantiomers are those with equal area and equal absorption profile. The D and L peaks were confirmed by injecting a standard of racemic solution of **1b**, **2b** and **3b** and observing the resulting chromatogram (Table 2, Figure 3 and Supplementary Materials, Figure S14). For **2b**, we also injected pure (\(-\))-**2b** (Figure 3). From the above, it was noted that the first peak, with a retention time of 19.77 min (Area%: 45.8028), was for enantiomer L and the second peak with a retention time of 21.56 min (Area %:40.2158) was for enantiomer D of compound **2b**. \begin{table}
\begin{tabular}{c c c c c c c} \hline \hline
**Entry** & **Benzyl Halide** & **Product** & **Base a ** & **Solvent** & **Temperature** & **t (h)** & **Yield (\%)** \\ \hline
**1** & **1a** & **(\(\pm\))-1b** & DBU c ** & Toluene & 90 cC & 12 & 50 \\
**2** & **2a** & **(\(\pm\))-2b** & K\({}_{2}\)CO\({}_{3}\) & CH\({}_{3}\)CN & 60 cC & 12 & 67 \\
**3** & **2a** & **(\(\pm\))-2b** & K\({}_{2}\)CO\({}_{3}\) & EtOH & Rt & 12 & Nr b  \\
**4** & **2a** & **(\(\pm\))-2b** & KOH & EtOH & Rt & 12 & Nr b  \\
**5** & **2a** & **(\(\pm\))-2b** & NaOCH\({}_{3}\) & Acetone & Rt & 12 & Nr b  \\
**6** & **2a** & **(\(\pm\))-2b** & NaOH & Acetone & 50 cC & 2 & Nr b  \\
**7** & **1a** & **(\(\pm\))-1b** & NEt\({}_{3}\) & CH\({}_{3}\)CN & 60 cC & 4 & 72 \\
**8** & **2a** & **(\(\pm\))-2b** & NEt\({}_{3}\) & CH\({}_{3}\)CN & 60 cC & 4 & 89 \\
**9** & **3a** & **(\(\pm\))-3b** & NEt\({}_{3}\) & CH\({}_{3}\)CN & 60 cC & 4 & 56 \\
**10** & **2a** & **(\(-\))-2b** & NEt\({}_{3}\) & CH\({}_{3}\)CN & 60 cC & 4 & 82 \\
**11** & **2a** & **(\(\pm\))-2b** & NEt\({}_{3}\) & no solvent & 60 cC & 1 & 50 \\
**12** & **2a** & **(\(\pm\))-2b** & NEt\({}_{3}\) & H\({}_{2}\)O & 60 cC & 1 & 38 \\ \hline \hline \end{tabular}
\end{table} 
Table 1: Optimization of selective synthesis of lactate esters. \begin{table}
\begin{tabular}{c c c c c c} \hline \hline
**Entries** & **Compound** & **Column** & **\(\alpha\)1** ** & **Rs2** ** & **Conditions (\(n\)-Hexane:\(i\)-Propanol)** & **\(\Lambda_{\text{obs}}\)** \\ \hline
**1** & &
\begin{tabular}{c} Chiralcel \\ OD-H \\ Chiralpak IA \\ (\(R\),\(R\))-Whelk \\ O2 \\ \end{tabular} & 1.05 & 1.77 & 98:2 & 210 nm \\ \hline
**4** & **2b** &
\begin{tabular}{c} Chiralcel \\ OD-H \\ Chiralpak IA \\ O2 \\ \end{tabular} & 1.08 & 3.24 & 90:10 & 230, 254 nm \\
**1.13** &
\begin{tabular}{c} Chiralpak IA \\ O2 \\ \end{tabular} & 1.04 & 1.17 & 90:10 & 230, 254 nm \\ \hline
**7** & **3b** &
\begin{tabular}{c} Chiralcel \\ OD-H \\ Chiralpak IA \\ O2 \\ \end{tabular} & 1.09 & 2.03 & 70:30 & 230, 254 nm \\
**1.18** &
\begin{tabular}{c} Chiralpak IA \\ O2 \\ \end{tabular} & 1.08 & 2.12 & 70:30 & 230, 254 nm \\
**1.19** &
\begin{tabular}{c} Chiralpel \\ OD-H \\ Chiralpak IA \\ O2 \\ \end{tabular} & 1.08 & 2.12 & 70:30 & 230, 254 nm \\ \hline \hline \end{tabular}
\end{table} 
Table 2: Chiral HPLC-DAD analysis of lactate derivatives. First, lactate ester **1b** was analyzed. As reported (Table 2, entries 1-3), the separation factors and resolution factors are low, and in one case (Table 2, entry 3) no separation was observed, even after increasing the hexane/_i_-propanol ratio. On the other hand, lactate **2b** was more successful (Table 2, entries 4-6). Interesting separations were achieved with the first two columns, whereas (_R_,_R_)-Whelk O2 showed lower performance (\(\alpha\) = 1.04; Rs = 1.17). Between Chiralcel OD-H and Chiralpak IA, the latter gave the best separation factor (1.13 vs. 1.08). Finally, lactate **3b** also gave satisfactory separations with the first two columns (Table 2, entries 7-8), whereas (_R_,_R_)-Whelk O2 gave no separation.