Longibornane

An important characteristic of medium-sized alicyclic rings is the ease with which transannular reactions arising from proximity of atoms occur (e.g. see 103). In the preferred conformation of the four-carbon bridge in the longifolane (155) and longibornane (156) systems, the proximity of the C-3, C-10 and C-2, C-9 positions, respectively has been responsible for interesting transannular reactions, both of homolytic and heterolytic types. 

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