Scale-Up Synthesis of IID572: A New β‑Lactamase Inhibitor

The new potentially best-in-class β-lactamase inhibitor IID572 was discovered by a late-stage functionalization approach. An alternative synthesis was developed to satisfy the short-term material need for toxicological studies in animals. The new synthetic strategy was built on two key features, an intramolecular azomethine ylide [3 + 2] cycloaddition that allowed the efficient formation of molecular complexity from readily available starting materials and an enzymatic resolution that resulted in high optical purity of a key intermediate.