Synthesis of Novel Calix[4]arenocrowns via Ring-closing Metathesis

A series of novel calix[4]arenocrown derivatives 8a–8c in a cone conformation, in which the lower rim and the upper rim were connected via ring-closing metathesis (RCM) reaction have been synthesized in good yields, and their structures were characterized by 1H NMR, 13C NMR, IR, MALDI-TOF MS techniques and elemental analyses.