A Biocatalytic Route to Highly Enantioenriched β‐Hydroxydioxinones

A novel biocatalytic system to access a wide variety of β‐hydroxydioxinones from β‐ketodioxinones employing commercial engineered ketoreductases has been developed. This practical system provides a remarkably straightforward solution to limitations in accessing certain chemical scaffolds common in β‐hydroxydioxinones that are of great interest due to their diversification capabilities. A few highlights of this system are that it is high yielding, highly enantioselective, and chromatography‐free. We have demonstrated both a wide substrate scope and a high degree of scalability.