Hydroxylation of Dodecanoic Acid and (2 R ,4 R ,6 R ,8 R )‐Tetramethyldecanol on a Preparative Scale using an NADH‐ Dependent CYP102A1 Mutant

Cytochrome P450 CYP102A1 from Bacillus megaterium is a fatty acid hydroxylase which catalyses the highly regioselective hydroxylation of branched fatty alcohols like (2 R ,4 R ,6 R ,8 R )‐tetramethyldecanol ( 4 ). The product of this reaction (2 R ,4 R ,6 S ,8 S )‐tetramethyldecane‐1,9‐diol ( 3 ) can be used in synthesis of macrolide antibiotics. For setting up the biooxidation process on a preparative scale a monophasic aqueous reaction system has been established. The system was optimised using an NADH‐dependent CYP102A1 mutant, dodecanoic acid as a model substrate and takes advantage of randomly methylated beta‐cyclodextrins for the solubilisation of hydrophobic substrates. In the reaction with 50 m M of dodecanoic acid a total turnover number of 66,700 and substrate conversion of 66.7 % could be reached. The total turnover number of a CYP102A1 mutant in the reaction with 23.4 m M (2 R ,4 R ,6 R ,8 R )‐tetramethyldecanol 4 was 17,290 and substrate conversion reached 74 %. The reaction on a preparative scale yielded 420 mg of (2 R ,4 R ,6 S ,8 S )‐tetramethyldecane‐1,9‐diol ( 3 ) in 60 % de . The major diastereomer 3a has the (2 R ,4 R ,6 S ,8 S ,9 R )‐configuration. The configuration of 3a was determined by an X‐ray single crystal structure analysis of the corresponding bis‐dinitrobenzoate 5a .