Remote Control of the C-3-C-4 Double-Bond Epoxidation of a Chiral 1,2-Dihydroquinoline: Application to the Synthesis of (-)-(R)-Sumanirole (PNU-95666E)

A twelve‐step synthesis of (–)‐(R)‐sumanirole starting from quinoline is described. The first synthetic approach, using a chiral Reissert adduct, was too problematic to be pursued further. In the second successful approach, the authors took advantage of the stereoselective epoxidation of a 1,2‐dihydroquinoline bearing an Evans' chiral auxiliary at N‐1. A twelve‐step synthesis of (–)‐(R)‐sumanirole hydrochloride has been developed from quinoline. In the successful approach, the key reaction is a diastereoselective epoxidation of the C‐3–C‐4 double bond of a 1,2‐dihydroquinoline bearing a chiral oxazolidinone‐derived auxiliary at N‐1.