ipso-Acylation of 5,13-di-tert-butyl-8,16-dimethyl[2.2]metacyclophane with acid anhydrides: Through-Space Electronic Interaction among the Two Benzene Rings

Abstract

Acylation of 5,13-di- tert-butyl-8,16-dimethyl[2.2]metacyclophane with acid anhydrides led to mono- ipso-acylation at the tert-butyl group to give 5-acyl-13- tert-butyl-8,16-dimethyl[2.2]metacyclophanes, from which the second electrophilic substitition with acid anhydrides can be strongly suppressed because of deactivation of the second aromatic ring by acyl group introduced by the through-space electronic interaction.