M. Mascal et al., Calixhydroquinones: a novel access to conformationally restricted, meta-substituted calixarenes, J CHEM S P1, (23), 1999, pp. 3435-3441
An efficient and versatile synthetic route to calixhydroquinones is describ
ed. These macrocycles are activated towards meta substitution, and reaction
with bromine gives the first examples of persubstituted, phenol-derived ca
lixarenes. The effect of meta substitution on calixarene mobility is demons
trated by the fixation of an otherwise mobile calix[4] system in the partia
l cone conformer, and the slowing of the ring inversion rate in calix[8]are
nes.