15460-06-7Relevant articles and documents
ASYMMETRICALLY SUBSTITUTED CALIXARENES; A TWO-DIMENSIONAL 1H NMR STUDY OF A TETRAESTER DERIVATIVE IN THE CONE-CONFORMATION
Zetta, Lucia,Wolff, Artur,Vogt, Walter,Platt, Karl-Ludwig,Boehmer, Volker
, p. 1911 - 1924 (1991)
Several new chiral calixarenes with three or four different substituents in the p-position have been prepared by fragment condensation.Standard derivation procedures always led to the formation of mixtures of various conformational isomeres from which the derivative in the cone-conformation could be isolated only by preparative HPLC.For a tetraester derivative it was shown by two-dimensional 1H NMR spectroscopy, that due to the different substituents the cone-conformation is strongly distorted.The sodium complex of this tetraester, however, assumes a regular cone-conformation again.