Enolate anions, arylation effects

Seven-membered and Larger Rings. The previously mentioned photochemical substitution of an aryl halide by an enolate anion (5rn1 reaction) has been effectively utilized in the synthesis of six-, seven-, eight-, and ten-membered rings. The most notable application was to the synthesis of cephalotaxinone (116) (Scheme 37), Other workers have used photochemical dehydro-halogenation reactions to prepare related compounds. ... 

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