For protein expression and screening, all transfer steps were performed using Hamilton liquid-handling robots. The ligated libraries were transformed into chemically competent E. coli BL21 (DE3) cells. Libraries were arrayed in 96-well plates, expressed and evaluated for improved activity as described in P450 panel screening. Conversion of individual mutants were normalized to the average of the 6 parent clones of that plate. Mutants that demonstrated increased activity were rescreened as purified proteins, that were produced and purified as described above, but starter cultures were inoculated from glycerol stocks prepared from the original overnight cultures. (R)-2-((4-Iodophenoxy)methyl)-2-methyloxirane was prepared according to a modified procedure from Singh. V AD-mix-α (1 g) was dissolved in water: tert-Butyl alcohol (1:1, 10 mL) and cooled to 0 °C. 1-Iodo-4-((2-methylallyl)oxy)benzene was added (272 mg, 1 mmol) and the reaction stirred overnight. Sodium sulfite (483 mg, 3.8 mmol) was added and the reaction stirred for 1 h at room temperature. The mixture was diluted with water (10 mL) and extracted with dichloromethane. The organic layer was dried over MgSO4, filtered and concentrated under vacuum. Column chromatography on silica gel with using ethyl acetate (50%) in petroleum ether as the eluent gave the dihydroxylation product (103 mg, 0.3 mmol, 33%). The diol (103 mg, 0.3 mmol) and triethylamine (57 µL) were dissolved in dichloromethane and cooled to 0 °C. Methane sulfonyl chloride (17 µL, 0.2 mmol, 0.6 equiv.) was added dropwise and the reaction mixture was stirred for 2 h at room temperature. The crude residue was concentrated under vacuum and dissolved in ethyl acetate (3 mL). DBU (60 µL) was added and the reaction mixture was stirred for 2 h. Water was added, the product was extracted with ethyl acetate and then the organic layer was concentrated under vacuum. The crude material was analytically pure and NMR data matched that of the racemic product 2-((4-iodophenoxy)methyl)-2-methyloxirane (3b), (90% e.e.). Chiral HPLC conditions: Chiralpak IE (Hexane/EtOH = 98/2, 0.5 mL min -1 , 30 °C) tR = 18.1 (minor), 18.8 (major) minutes.