Viktoria A Ikonnikova, Kirill D Kungurtsev, Pavel N Solyev, Vladislav A Lushpa, Mikhail S Baranov, Dmitry A Skvortsov, Andrey A Mikhaylov
Development of skeletal editing methods offers new horizons for the acceleration of drug discovery. An original aza-Favorski-type approach is described for the ring contraction of benzazepine-2-ones, providing versatile tetrahydroquinoline-2-carboxylic acids. The sequence employing silylation and Pb(OAc)4-promoted oxidative ring contraction affords variously substituted N-protected derivatives in ≤67% yields. The approach can also be applied to higher homologues, although with a lower efficiency.