Spiro alkanes, polymerization

FIGURE 6.30 a,cu-Bis(tocopheryl)alkanes (36) and other a, >-bis(hydroxyphenyl)-alkanes (37-40) as starting materials for the spiro oligomerization/spiro polymerization reaction. 

FIGURE 6.31 Spiro polymerization of a, spiro polymers 41 carrying spiro dimer units linked by alkyl chains. Reduction of 41 converts the spiro dimer units into ethano-dimer units, resulting in polytocopherols 42. 

Prior knowledge has shown the value of introducing cyclopropane systems into macromolecules. A number of isolated studies have been carried out on the polymerization of such structures (10, 14, 28), principally on cyclopropane (28) and isopropylcyclopropane. Attention was directed toward three types of structures—i.e., the 1,1-dichlorocyclopro-panes, the bicyclo[n.l.0]alkanes, and the spiro [2.n] alkanes. In each case, the effects involved appeared highly complex the polymers formed have not yet all been characterized, and it is thought that a comparison with the model structures expected from rupture of one or the other of the cyclopropane bonds may be of value. 

Polymerization of Spiro[2.n]alkanes. Spiro[2.6]nonane (M5), spiro [2.7]decane (M(i), and spiro[2.1 ljtetradecane (M7) were prepared from the corresponding methylenecycloalkanes (methylenecycloheptane, meth-ylenecyclooctane, and methylenecyclododecane, respectively) by the Simmons and Smith reaction (14) see Equation 8. 

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