General procedure F for the reduction of esters to alcohols. To a solution of the ester (0.5 mmol, 1 equiv.) in THF (dry), NaBH4 (3 mmol, 6 equiv.) was added portion-wise at 0 °C. MeOH (2 mL) was added dropwise, and then the reaction mixture was stirred at room temperature for 3 h. The completion of the reaction was confirmed by TLC, and it was quenched with sat. NH4Cl solution (20 mL). The mixture was extracted with EtOAc (3 × 50 mL) and the organic layers were washed with sat. NH4Cl solution (2 × 20 mL) and brine (2 × 50 mL). The organic phase was dried over Na2SO4, concentrated under reduced pressure, and the residue purified by flash column chromatography to afford the alcohol.