Remarkable metal template effects on selective syntheses of p-t-butylcalix[4]arene conformers

Article abstract of DOI:10.1016/S0040-4039(00)97270-8

It was found that the conformer distribution in tetra-O-substitution of p-t-butylcalix[4]arene is remarkably affected by metal species in base: in particular, 100% 'cone' selectivity in the presence of Na₂CO₃ is changed to 100% 'partial cone' selectivity in the presence of Cs₂CO₃ in the reaction with ethyl bromoacetate.