Conformational isomerism of the calix[6]arenes: isolation of two conformational isomers of the 1,2-bis(p-tert-butylbenzyl)ether of the p-tert-butylcalix[6]arene

Two conformational isomers of the l,2-bis-p-tert-butylbenzyl) ether of p- tert-butylcalix[6larene have been isolated by chromatography, and their conformational features have been inferred from NMR spectral evidence, VT-NMR studies, and MM2 molecular mechanics calculations.