Cyclodecapentaene synthesis

Cyclobutanc, angle strain in. 115-116 conformation of. 115-116 molecular model of, 116 photochemical synthesis of, 1190 strain energy of, 114 torsional strain in, 115-116 Cyclodecane, strain energy of. 114 Cyclodecapentaene, molecular model of, 525, 540... 

To be aromatic, a molecule must have 4u + 2 jt electrons and must have cyclic conjugation. 1,3,5.7,9-Cyclodecapentaene lullills one of these criteria but not the other and has resisted all attempts at synthesis. Hxplain. 

The central molecules from this saga of the 1960s are the potentially aromatic cyclodecapentaenes and bullvalene, a compound of 10/3 faces. Efforts directed to the synthesis of these compounds involved thermal, photochemical, and metal-catalyzed processes which not only accomplished the major task but also generated... 

PROBLEM 13.50 Vogel and Roth s synthesis of the bridged cyclodecapentaene (1) is outlined helow. Supply the missing reagents (a, b, c, and d) and an arrow formalism for the last step. 

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