General procedure for analytical scale biotransformation Unless otherwise stated, biotransformations were performed in glass reaction vessels, using the specified alkene (2 mM) and purified enzyme (0.2 µM) in 100 mM KPi buffer pH 7 containing 50 mM glucose, 0.5 mM NADPH and 1 mg mL -1 GDH with 15% MeOH. The reaction mixture was incubated for 10 min with shaking at 750 rpm. The reaction was quenched with 1 volume MeCN with precipitated protein removed by centrifugation (4000 rpm for 10 minutes) and the supernatant used for UPLC and chiral HPLC analysis.