Synthesis of indolidines by the 1,3-dipolar cycloaddition of azides with methylenecyclopropanes followed by cyclopropyumine rearrangement

Article abstract of DOI:10.1016/S0040-4039(00)97867-5

Cyclic imines 6a and 6b were obtained by the intramolecular 1,3-dipolar cycloaddition of azides with methylenecyclopropanes. Acid catalyzed rearrangement produced bicyclic (-)-enamines 7, which upon reduction provided indoilizidenes 8. A similar strategy was used for the synthesis of (-)-8a-epi-desacctoxyslaframine 16.