Myers and co-workers have pioneered the application of transannular anionic cyclization reactions in the synthesis of the 5,9-fused bicyclic core of kedarcidin chromophore and neocarzinostatin chromophore.
 In the first incarnation, hydride delivery to a cyclic tetrayne was guided by aluminum coordination to a proximal alkoxide, thus generating the desired enediyne core in one step via two successive 5-exo-dig–type cyclizations.
Later-generation syntheses of the core intercept this cascade cyclization, relying on lithium-halogen exchange on a cyclic vinyl bromide to generate the vinyl anion precursor to the bicyclic product.

The bicyclic core of C10-epi-kedarcidin chromophore was prepared by the sequential application of three carbon-carbon bond forming reactions, as shown in the retrosynthetic schematic above.
First, a Sonogashira coupling was carried out between a bromovinyl electrophile and alkynyl nucleophile; ring closure to give a cyclic triyne was then accomplished by Glaser coupling of two terminal alkynes.
The 5,9-fused bicyclic core was established by in situ generation of a vinyllithium species that underwent transannular 5-exo-dig cyclization.
Myers and co-workers have pioneered the application of transannular anionic cyclization reactions in the synthesis of the 5,9-fused bicyclic core of kedarcidin chromophore and neocarzinostatin chromophore.  In the first incarnation, hydride delivery to a cyclic tetrayne was guided by aluminum coordination to a proximal alkoxide, thus generating the desired enediyne core in one step via two successive 5-exo-dig–type cyclizations. Later-generation syntheses of the core intercept this cascade cyclization, relying on lithium-halogen exchange on a cyclic vinyl bromide to generate the vinyl anion precursor to the bicyclic product.
The bicyclic core of C10-epi-kedarcidin chromophore was prepared by the sequential application of three carbon-carbon bond forming reactions, as shown in the retrosynthetic schematic above. First, a Sonogashira coupling was carried out between a bromovinyl electrophile and alkynyl nucleophile; ring closure to give a cyclic triyne was then accomplished by Glaser coupling of two terminal alkynes.The 5,9-fused bicyclic core was established by in situ generation of a vinyllithium species that underwent transannular 5-exo-dig cyclization.
Kedarcidin