Hydrocarbons bridged polycyclic

Reaction 7 —> 9 is general for synthesis of bridgehead azides of bridged polycyclic hydrocarbons. Another route which was studied as a general synthesis is shown in Fig. 2.14. 

Jorgensen WL (1975) Chemical consequences of orbital interactions. II. Ethylene and butadiene bridged polycyclic hydrocarbons containing three- and four-membered rings. J Am Chem Soc 97 3082-3090... 

These may be classified into four chemical groups Chlorinated hydrocarbons which include dico-phane (DDT) and its analogues (e.g. dicofol and methoxychlor), hexachlorocyclohexMie isomers (e.g. lindane), and bridged polycyclic chlorinated compounds (e.g. chlordane) ... 

Chlorinated Hydrocarbons These insecticides, e.g. dicophane and its analogues, isomers of hexachlorocyclohexane, and bridged polycyclic chlorinated compounds, may be chromatographed satisfactorily without prior deri-vatisation. A typical separation is shown in Fig. 1, using the dual detection system. Although greater... 

Bridged polycyclic chlorinated hydrocarbon insecticides include the dimethanonaphthalenes and methanoindenes. Their spectra are dominated by retro Diels-Alder fragmentation reactions which are accompanied, or preceded, by expulsion of Cl and/ or HC 1. A typical dimethanonaphthalene is aldrin, the mass spectrum of which is shown in Fig. 4. The corresponding epoxide of this compound, dieldrin, shows similar features. 

Polycyclic aromatic hydrocarbons (PAH) are produced by the combustion, under fuel rich conditions, of almost any fuel. Although a few PAH with vinylic bridges (such as acenaphthylene) are lost, most PAH are quite stable in the atmosphere and eventually accumulate in environmental sinks such as marine sediments. Spatial and historical measurements of PAH in sediments Indicate that these compounds are stable, conservative markers of man s energy producing activities. 

Polycyclic aromatic hydrocarbons can be bent by bridging in a similar fashion. Two recent examples of such [n] cydophanes are azulenophane 116 [77] and 1,8-dioxa[8](2,7)pyrenophane 117 [78]. X-ray structure analysis revealed an angle of 3.7° between the azulene ring planes, whereas the pyrene moiety is bent by nearly 90°. 

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