Regio- and stereoselective oxygenation of proline derivatives by using microbial 2-oxoglutarate-dependent dioxygenases

We evaluated the substrate specificities of four proline cis-selective hydroxylases toward the efficient synthesis of proline derivatives. In an initial evaluation, 15 proline-related compounds were investigated as substrates. In addition to L-proline and L-pipecolinic acid, we found that 3,4-dehydro-L-proline, L-azetidine-2-carboxylic acid, cis-3-hydroxy-L-proline, and L-thioproline were also oxygenated. Subsequently, the product structures were determined, revealing cis-3,4-epoxy-L-proline, cis-3-hydroxy-L-azetidine-2-carboxylic acid, and 2,3-cis-3,4-cis-3,4-dihydroxy-L-proline.