Aldol addition of acetone (2a) to phenylacetaldehyde (1a) catalyzed by EcFSA D6 N and subsequent transamination reaction catalyzed by AtTA in the presence of d‐Ala. A) One pot reaction of aldol addition and subsequent transamination of 1a and 2a with AtTA mediated side reaction to 9a. B) Product distribution of the aldol reaction and the subsequent transamination in a one‐pot setup with following conditions: (I) One‐pot concurrent cascade; (II) One‐pot, two‐step cascade, EcFSA removed via heat‐shock after completion of aldol addition and then AtTA added; (III) One‐pot, two‐step cascade, 15 eq d‐alanine instead of pyruvate removal with LDH and no EcFSA elimination (IV) One‐pot, two‐step cascade in the presence of EcFSA; (V) One‐pot, two‐step cascade, EcFSA removed by heat‐shock and acetone purged by airflow; (VI) no AtTA added; i. e. control experiment. Reaction conditions: Triethanolamine (TEoA) buffer (50 mM, pH 8), horizontal shaking, 25 °C, 80 mM substrate (initial, 50 mM after AtTA addition), lactate dehydrogenase (LDH) to eliminate the pyruvate formed after the transamination reaction.