4.8. General Methods for Resting Cell Biotransformation

Reactions were performed in 50-mL screw-capped glass vials to prevent evaporation of the substrate/product. Shaking was performed in a heated ground-top shaker at 25 °C with 220 rpm. Approximately 3 g of resting cells of 48-h-grown age (wet cells) were resuspended in 10 mL of Na₂HPO₄-KH₂PO₄ buffer (100 mM, pH 7.0) containing 0.5 g of glucose and 10 mM 1a–1n. After 24 h, the reaction was stopped by centrifugation at 4000 rpm and at 4 °C for 20 min to remove cells. The supernatant (2 mL) was saturated with NaCl followed by extraction with 2 × 2 mL of HPLC eluent (n-hexane/i-PrOH = 95/5, v/v) by shaking for 5 min. The combined organic layer was dried over Na₂SO₄ and measured by HPLC for yield and ee.