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A cascade intramolecular azide-alkene 1,3-dipolar cycloaddition/Stork alkylation reaction has been developed for the synthesis of functionalized cyclic imines with a pyrroline and piperideine structures, employing readily available ω-azidodienes. [ABSTRACT FROM AUTHOR]

The first total synthesis of the natural alkaloid amphorogynine C is reported (2.9 % overall yield in 20 steps). The key steps include a Claisen-Johnson rearrangement and an intramolecular azide-olefin cycloaddition, followed by a reduction of the resulting imine. The construction of the pyrrolizidine skeleton was achieved by an alkoxide-mediatedlactone ring opening and subsequent cyclization of a conveniently functionalized bicyclic amine. Finally, the proposed structure of amphorogynine C was confirmed by single-crystal X-ray diffraction analysis. [ABSTRACT FROM AUTHOR]

A cascade intramolecular azide-alkene 1,3-dipolar cycloaddition/1,2 enamine and/or 1,4 enamine addition reaction sequence has been developed, and provides access to a variety of nitrogen containing heterocycles from readily available ω-azido alkenes. [ABSTRACT FROM AUTHOR]

Synthesis of the core skeletons of the polycyclic alkaloids lycopodine and porantherine has been accomplished employing as a key step an I ntramolecular A zide- O lefin C ycloaddition reaction (IAOC)/enamine addition/Mannich cascade reaction. Applying this methodology, the first synthesis of C 15 -desmethyl lycopodine has been developed. [ABSTRACT FROM AUTHOR]