Lithium in formation of triphenylene

Lithium ethoxide in condensation of benzaldehyde with triphenyldn-namylphosphonium chloride to form l,4-diphenyl-l,3-butadiene, 36 Lithium in formation of triphenylene from o-bromoiodobenzene, 106... 

A special reaction of this type is the formation of benzyne. o-Fluorobromobenzene reacts with lithium amalgam in ether or furan with an intermediate formation of benzyne. In the former medium, diphenylene and small amounts of triphenylene and 9,10-dimer-cura-9,10-dihydroanthracene were formed, whereas the major product (76%) in furan was 1,4-dihydronaphthalene-1,4-endoxide [64]. 

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