Dihalocyclopropanes, polymerization

This paper deals with the polymerization of several purely hydro-carbonated and gem-dihalocyclopropanic monomers. The influence of conjugation between a cyclopropane and one double bond, and the influence of the conjugation between two cyclopropanic groups is shown for several monomers, such as spiropentane, vinyl gem-dihalocyclopro-pane, and bicyclononene. 

Pyrolysis of dihalocyclopropanes was studied along with the effects of electrophilic reagents, and confirms the foregoing results (33-37). In many cases, those authors observed that polymeric residues, in addition to ally lie and diene-type products, were present at the end of pyrolysis. The formation of these polymers confirms the hypothesis that the dihalocyclopropanes are monomers that can be polymerized either by cationic processes or by the action of transition-metal complex catalysts. 

Polymerization of Dihalocyclopropane with an Adjacent Phenyl Group. The monomers shown in Equation 25 are preparated by adding... 

Polymerization of Bicyclo[6.1.0]non-4-ene and 9,9-Dihalobicyclo-[6.1.0]non-4-ene. Bicyclo[6.1.0]non-4-ene and 9,9-dihalobicyclo [6.1.0]-non-4-ene (M26, Equation 32) have the special feature of having two unsaturated sites that can react separately or simultaneously—that is, one C=C double bond and a cyclopropane (47-50) 9,9-dihalobicyclo [6.1.0]-non-4-ene was synthesized by adding dihalocarbene to 1,5-cyclooctadiene (yield 56%). Reduction of the dihalocyclopropane group with a Na/ hydrated methanol system yielded bicyclo[6.1.0]non-4-ene (yield 85%). 

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