Cyclooctatetraene with cubane

Let us close this account of simple prismanes with a look at hexaprismane. The synthesis of cubane was reported in 1964 pentaprismane was said (1974) to show extraordinary synthetic inaccessibility [16], but was made in 1981 [13] and hexaprismane has so far (early 2007) resisted all attempts at synthesis [5]. As Hopf points out [5], hexaprismane can in principle be assembled from two benzene rings or from cyclobutadiene and cyclooctatetraene ... 

Cyclooctatetraene (COT), a An non-aromatic hydrocarbon, is only one of the many (CH)s compounds, but it is a central character. The other isomers, many of which interconvert with COT by thermal and photochemical pathways, include bicyclo[4.2.0]octa-2,3,7-triene (BOT), semibullvalene (SB), barrelene (B), tricyclo[3.3.0.0 ]octa-3,7-diene (TOD), the cyclobutadiene dimers (CBD), tetracyclo[4.2.0.0. " 0 ]oct-7-ene (TOE), cubane (C), tetracyclo[4.2.0.0. 0 ] octene - the intramolecular Diels-Alder isomer of BOT (IDA), tetracy-... 

Alternatively, <7,(7 excited states of simple cyclobutanes seem to be accessible on 185-nm excitation The quantum yields are = 0.12 for substrate consumption and Op = 0.10 and Op = 0.03 for the formation of octa-1,7-diene and cyclohexene . Similarly, cubane (55) decomposes on 185-nm excitation with a quantum yield of O = 0.08 to give cyclooctatetraene and benzene (equation 24). 

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