After creating a series of traditionally chiral calixarenes (through the addition of a chiral substituent group on the top or bottom rim of the macrocycle,) the first inherently chiral calixarenes were synthesized in 1982, though the molecules were not yet described as such.  The inherently chiral calixarenes featured an XXYZ or WXYZ substitution pattern, such that the planar representation of the molecule does not show any chirality, and if the macrocycle were to be broken open, this would produce an achiral linear molecule.  The chirality in these calixarenes is instead derived from the curvature of the molecule in space.