Acid-Catalyzed Rearrangements for a Diastereoselective Entry into a New Fused Hexacyclic Heterocycle: (5RS,7aRS,12RS,14aRS,)-4,5,7a,11,12,14,14a-octahydro-5,12-dimethyl-diindolo [1,7-bc: 1′,7′-gh][2,6] naphthyridine

The title compound 1 was obtained in 10.3% overall yield via two acid-catalyzed rearrangements and pyrrolidine formation. Thus, bi-oxindole 6 afforded exclusively the thermodynamically stable cis-diazachrysene 7 which, after allylation, followed by aza-Claisen rearrangement gave alcohol 2 . Pyrolytic ring closure of the latter yielded 1 in highly diastereoselective fashion.