Lewis acid-catalyzed reactions of .alpha.,.beta.-unsaturated N,N-dimethylhydrazones with 1,4-benzoquinone. Formation of indoles by a novel oxidative rearrangement
Lewis acid-catalyzed reactions of .alpha.,.beta.-unsaturated N,N-dimethylhydrazones with 1,4-benzoquinone. Formation of indoles by a novel oxidative rearrangement
A pentacyclic aza-aromatic alkaloid, cystodamine (6), and its isomer (11) were synthesized from 7-(or 6-)bromo-4-chloro-5,8-quinolinedione (1, 8) and o-nitrocinnamaldehyde dimethylhydrazone (2) using hetero Diels-Alder reaction. (C) 1997 Elsevier Science Ltd.