Protic-Solvent-Mediated Cycloisomerization of Quinoline and Isoquinoline Propargylic Alcohols: Syntheses of (±)-3-Demethoxyerythratidinone and (±)-Cocculidine


  • The research was supported by a grant from the NIH-NIGMS (RO1 084906), the NSF-USA (graduate fellowship to STH), and Daiichi Sankyo. We thank Daniel Sanner and Christina Kraml of Lotus Separations (Princeton, NJ (USA)) for the preparative-scale separation of the enantiomers of 28.


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Putting the “benz” in indolizinones: A cycloisomerization approach to benz[g]indolizinones and benz[e]indolizinones provides the first general route to these unique azacycles (see example). The utility of the benzindolizinone products was demonstrated by the application of this method to the total synthesis of the Erythrina alkaloids 3-demethoxyerythratidinone and cocculidine.