General Procedure for Preparative-Scale Biocatalytic Aldol Addition of Donor Molecules with Aldehydes

In a 50 mL Falcon tube were placed the components for the FSA reactions (same conditions used in the previous section) with a total reaction volume of 20 mL. Each reaction was set up in triplicate. For each unique aldehyde/donor combination the FSA that gave the highest conversion in the initial screen was chosen. The reaction mixtures were incubated at 25 °C at 250 rpm for 24 h. The reaction mixtures were filtered through Celite to remove protein and then extracted with EtOAc (3 × 80 mL). The organic layer was washed with brine (10 mL), dried over anhydrous MgSO₄, and concentrated by rotary evaporation. The crude residue was resuspended in minimal EtOAc and purified by flash chromatography (hexane/ethyl acetate 95/5–5/95).