Key points are not available for this paper at this time.
Condensation of 1,4-dimethoxybenzene (DMB) with paraformaldehyde in the presence of BF3.O(C2H5)2 gave novel para-bridged pentacyclic pillar DMB (DMpillar5arene). Moreover, para-bridged pentacyclic hydroquinone (pillar5arene) was prepared. Pillar5arene formed 1:1 host-guest complexes with dialkyl viologen and alkyl pyridinium derivatives. However, pillar5arene did not form complexes with the diadamantyl viologen derivative since a bulky adamantyl group was unable to thread the cavity of pillar5arene.
Ogoshi et al. (Sat,) studied this question.