Adamantane Friedel-Crafts reaction

Substitutions at the 2-position of adamantane are sterically hindered, 5, 1 processes being less affected than S 2 ones. Friedel-Crafts reaction of a 2-chloroadamantane (911) with benzene gives the 2-phenyladamantane in high yield if the adamantane concentration is low (1 %). At 20% w/v concentration, intermolecular hydride transfers lead to the formation of a tertiary cation and hence the 3-phenyladamantane. ... 

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