A Novel Stereoselective Synthesis of <Emphasis Type="Italic">cis</Emphasis>-Configured Erythrinane and Erythrinane Type Analogues

Summary. N-Alkylation of certain angularly substituted heterocycles by C₂- and C₃-units provided appropriate precursors to construct stereoselectively the erythrinanone and several erythrinanone type analogues by intramolecular Friedel-Crafts acylation. The resulting aromatic ketones were catalytically reduced affording the corresponding parent frameworks including the hitherto unknown tetracyclus A-norschelhammerane. On the other hand, the stereoselective reduction of the carbonyl moiety offered a convenient approach to 11-hydroxylated erythrinanes with the natural occurring -configuration. The structures and the stereochemistry of the target compounds were proved by NMR spectroscopy.Part of PhD thesis, LMU München, D